Submerging It Is a Drying Question, Not a Washing One

The short answer: a memory foam pillow never goes in a washing machine, and the guides split evenly on whether you can submerge it in a sink instead. Both camps are right about different situations, because the risk is not the water going in, it is the water not coming out. Foam holds moisture in its core for a day or more, and a pillow that feels dry on the outside while still damp inside grows mildew where you cannot see it. So the honest rule is this: submerge it only if you can guarantee twenty-four hours of airflow and pass a paper towel test afterwards. If you cannot, vacuum it and spot clean instead. And if yours is shredded rather than solid foam, the answer changes again.

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Why the advice contradicts itself

Search this and you will find two confident and opposite answers to the central question. One set of guides walks you through filling a bath, submerging the pillow completely and squeezing the water through it. Another set states plainly that you must never submerge memory foam, that too much water degrades it and that spot cleaning is the only safe route.

Nobody in either camp explains why the other exists, and the resolution is not a compromise between them.

Everyone agrees on the machine

Start with what is not in dispute, because it is unusually unanimous. A memory foam pillow does not go in a washing machine, at any setting, and it does not go in a tumble dryer at all.

The agitation and the spin cycle tear the open cell structure, so the foam breaks apart or loses its shape permanently. Dryer heat is worse: it degrades the foam and can genuinely melt it. Those two facts are stated by every source on the subject including the manufacturers, and they are the reason this article exists rather than a line in a general pillow guide.

The disagreement is really about drying

Here is what neither camp says out loud. Water going into foam is not the problem. Water staying in foam is the problem.

Foam is an open cell structure that behaves like a sponge: it takes liquid in readily and gives it up to the air very slowly, because the moisture is held by capillary action rather than sitting on a surface. A pillow that has been submerged holds water in its middle long after the outside feels dry, and a warm damp core with a cover back on it is an ideal place for mould and mildew.

So submersion is not inherently wrong. It is a commitment. If you can press most of the water out mechanically, give the pillow twenty-four hours of moving air, and verify the core is dry before it goes back on the bed, submerging is a genuinely more thorough clean. If any of those three is in doubt, spot cleaning is the better answer and it is not a lesser one.

Which is why the guides both work

The sources recommending submersion are describing an ideal case: a warm breezy day, a pillow pressed between towels, plenty of time. The sources warning against it are protecting readers who will wash a pillow on a wet Tuesday evening and put it back on the bed the following morning.

Both are giving reasonable advice for the reader they imagine. Knowing which reader you are is the whole decision.

The rest of this article is that decision applied: which kind of foam you have, which method suits it, and how to dry whichever you choose so the pillow survives being cleaned.

Find your method in 3 taps

What kind of foam, what is wrong with it, and how much drying time you actually have. Those three decide between a bath, a cloth and a vacuum.

Which foam you have, and what it changes

The first two columns never vary. The third is where the guides split, and the fourth is why.

The shredded row is the one people miss. Shredded foam is fill rather than a single block, so water moves through it and out again far more readily, and some shredded pillows are sold as machine washable for exactly that reason. If your pillow squashes down and the contents shift when you move it, check the care tag before assuming the solid-foam rules apply.

And the branded row is the quiet good news. Most Tempur-Pedic and similar pillows have a removable cover, and that cover is what absorbs the sweat, oils and hair. Washing it handles most of what makes a pillow feel dirty, without any of the drying risk.

The two methods, step by step

Choose one before you start rather than escalating halfway through, because a pillow that gets partially wet is the worst outcome of all.

The dry method, for most situations

1. Take the cover off and wash it separately. Cold, gentle cycle. This alone handles most of what makes a pillow feel unclean.
2. Vacuum both faces and the sides with an upholstery attachment, which lifts dust, skin cells and hair out of the surface.
3. Sprinkle dry bicarbonate of soda over one face, leave it an hour or overnight, then vacuum it off thoroughly. Turn the pillow and repeat.
4. Spot treat any marks with a barely damp cloth, a little mild detergent, and light pressure from the outside of the mark inward. Blot with plain water afterwards to lift the soap, and dry that patch with a fan.

The wet method, when the pillow has earned it

1. Start in the morning. Not the evening. You need the daylight hours for drying and this is the step that decides whether the whole thing was a good idea.
2. Fill a bath or large basin with cool or lukewarm water and a small amount of mild detergent. Not hot: heat degrades foam.
3. Submerge and squeeze gently. Press down repeatedly to push soapy water through the foam and let it draw back in. That squeezing is the cleaning. Never scrub, twist or wring, which tears wet foam.
4. Drain and rinse the same way in clean water, repeating until no suds appear when you press. Detergent left in foam holds moisture and attracts dirt.
5. Press the water out between towels. Lay the pillow on a thick towel, put another on top, and press down with your body weight. Roll the whole thing up and press along its length. Repeat with dry towels until nothing more transfers.
6. Dry flat with a fan, turning every few hours. Flat rather than hanging, since a hanging wet pillow lets everything migrate downward. Never a dryer, never a hairdryer, never a radiator.

One thing to know about frequency: a memory foam pillow wants cleaning roughly every three to six months, and the cover far more often than that. Repeated soaking degrades foam over time, so the wet method is a once-a-year operation at most rather than a routine.

The one that means you rarely do any of this

Everything above exists because sweat and body oils get into foam that cannot easily be washed. A zippered protector between the pillow and the pillowcase stops that happening, and it costs a fraction of the pillow it protects.

Two specifications on this one are worth naming, because most protectors state neither. It is GREENGUARD Gold certified and independently lab tested, which matters on something your face is against for eight hours, and it is free from vinyl, PVC and phthalates. The waterproof layer is a breathable membrane rather than a plastic sheet, so it does not rustle or trap heat.

The practical detail that makes it worth having: it is cut an inch wider and longer than standard pillow dimensions, which sounds trivial until you have fought a protector onto a memory foam pillow that will not compress.

Worth it or skip: Worth it on any memory foam pillow, because the pillow cannot be machine washed and the protector can. Skip it if your pillow already has a removable washable cover and you wash it monthly, which achieves much the same thing.

Check the zippered pillow protector on Amazon

Three more, by what you need

A terry-topped protector, if the plastic feel is what puts you off. The usual objection to pillow protectors is that they crinkle and sleep hot. This one has a cotton terry face over the membrane, so what your ear is against is fabric rather than laminate, and a micro zipper that closes fully rather than leaving a gap at the end. See the terry-topped protector →

A TPU-backed pair, for a bed with two pillows. Same principle with the waterproof layer named explicitly, which is unusual and useful, since TPU is more breathable than the vinyl backings that give protectors their reputation. Two is the sensible number: one on the pillow, one in the wash, because a protector in the machine means an unprotected pillow overnight. See the TPU-backed pair →

An enzymatic cleaner, for anything organic. Sweat, drool and anything biological leave compounds that detergent dilutes rather than breaks down, which is why a pillow smells again on a humid day after being cleaned. Enzymes digest them. Apply sparingly to a cloth rather than to the foam, allow the stated dwell time, and dry the area with a fan. See the enzymatic cleaner →

The same foam physics on a larger scale is in drying a wet mattress, and the version where the filling decides everything is in how to wash throw pillows.

Washed it and something went wrong? 2 taps

The quiz above is for choosing a method. This one is for a pillow that has already been through one, and it will tell you honestly what is recoverable.

People also ask about memory foam pillows

Can you put a memory foam pillow in the washing machine?

No, at any setting, and this is the one point every source on the subject agrees on including the manufacturers. The agitation and the spin cycle tear the open cell structure, so the pillow comes out with dense and hollow areas that never recover its shape. A tumble dryer is worse, because heat degrades foam and can genuinely melt it. The only exceptions are some shredded foam pillows, which are sold as machine washable specifically because the fill can move, so check the care tag before assuming.

Can you submerge a memory foam pillow in water?

The guides split evenly on this and both sides are right about different situations. Water going into foam is not the problem; water staying in foam is. A pillow that has been submerged holds moisture in its core for a day or more, and a damp core with a cover back on it grows mildew where you cannot see it. So submerge it only if you can press most of the water out between towels, give it twenty-four hours of moving air, and verify with a dry paper towel pressed into the middle. If any of those is in doubt, spot clean instead.

How do you wash a Tempur-Pedic pillow?

Wash the cover, spot clean the foam. Tempur-Pedic and most similar branded pillows have a removable, machine washable cover, and their own guidance is to avoid water immersion for the foam itself. That is convenient rather than restrictive, because the cover is what absorbs the sweat, oils and hair that make a pillow feel unclean. Cold gentle cycle for the cover, and for the foam a vacuum, dry bicarbonate of soda and spot treatment for any marks.

How long does a memory foam pillow take to dry?

Twenty-four hours with a fan on it after a submersion clean, and longer in a cold or humid room. One widely shared guide suggests four to six hours, which is realistic for a spot clean and far too short for a soaked pillow. Foam releases water slowly because the moisture is held by capillary action rather than sitting on a surface, and there is no way to speed that up that does not involve heat, which is the one thing that destroys foam. Test with a dry paper towel pressed firmly into the middle rather than judging by hand, since the surface always dries first.

Memory foam pillow FAQ

How often should I clean it?

The foam every three to six months, and the cover far more often, monthly or with the sheets. Repeated soaking degrades foam over time, so a full wet clean is a once-a-year operation at most. Vacuuming and dry bicarbonate of soda in between handle routine freshening without any drying risk at all.

Can I use a hairdryer to speed up drying?

No. Heat degrades memory foam and hardens latex, and a hairdryer concentrates it on one small area while doing nothing for the core. Even on a cool setting it is a very inefficient fan. A room fan moves far more air across the whole pillow, and that is the only method that reaches the middle without damage.

Why does my pillow smell after washing it?

Almost always because it was not fully dry when the cover went back on. The surface dries first and feels finished while the core stays damp, and a warm damp core under a cover is where mildew starts. Press a dry paper towel into the middle of each face: any moisture means it needs another day. If it passes and still smells, the odour is organic and needs an enzymatic cleaner rather than more washing.

Does bicarbonate of soda actually work on foam?

For odour, yes, and only when used dry. Sprinkled on and left an hour or overnight, it absorbs odour and draws oil out of the surface, then vacuums off. Dissolved into a spray it stops doing either and adds moisture to something you are trying to keep dry. And do not mix it with vinegar, which several guides suggest: they neutralise each other into salty water.

How long should a memory foam pillow last?

Two to three years of nightly use before it starts losing rebound, crumbling at the edges or flattening in the middle. If yours has gone lumpy without having been washed or heated, that is age rather than damage. A protector extends the useful life considerably, because most of what degrades a pillow is body oil and sweat rather than mechanical wear.

Can I put it in the sun to freshen it?

Briefly and in shade rather than direct sun. Sunlight has a genuine airing effect, and sustained heat is what damages foam, so a couple of hours outdoors on a breezy day in the shade gives you most of the benefit. Latex specifically must stay out of direct sun altogether, since it hardens and yellows permanently.

The memory foam pillow cheat sheet

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The Cozy Home Starter Checklist

A protector on a pillow you cannot wash is one of those small decisions that saves an afternoon later. This printable walks you through a home room by room, catching the things that quietly matter more than they look.

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Keep reading

• The Cover Is Not the Problem. The Filling Is
  The same principle applied to cushions, including the squeeze test for working out what is inside one with no label.
• Four Different Things, and Two of Them Ruin a Machine
  Protectors, pads and toppers, and why a foam topper is the large version of the pillow in this article.
• Sunlight Saves One Mattress and Destroys Another
  The same foam physics at the largest scale, with the 48-hour mould clock and why heat ruins latex specifically.
• Cozy Bedding Ideas: The Complete Guide to a Dreamy Bed (2026)
  How the pillow sits in the wider arrangement, and how many a bed actually needs.
• New Sheets Are Not Stiff. They Are Coated
  The layer that goes over the pillowcase, and why the first wash matters more than the thread count.

Decide the drying before you decide the washing

Every source agrees that a memory foam pillow never goes in a washing machine and never goes in a dryer. Where they split is whether you can submerge it in a sink, and half of them say yes with enthusiasm while the other half say never with equal confidence.

They are both right, because the question is not really about the water going in. Foam takes water readily and gives it up very slowly, so a submerged pillow holds moisture in its middle for a day or more, and a damp core under a cover is where mildew starts. Submersion is a commitment to twenty-four hours of airflow rather than a cleaning technique on its own.

So decide the drying first. If you have the day, the fan and the patience, submerging gives you a genuinely deeper clean. If you do not, wash the cover, vacuum the foam, use dry bicarbonate of soda and treat the marks, which is a real clean rather than a compromise. And press a dry paper towel into the middle before anything goes back on, because the surface will tell you what you want to hear and paper will not.

Mine went back on the bed after eight hours once, feeling perfectly dry, and smelled by the following weekend. The towel would have taken ten seconds.