Pillows spend a lot of time under your head so it can be gross to think about them not being washed. They really need to be washed occasionally. Pillows should be washed at least every 6 months. But I usually wash mine once a season. If you have multiple pillows rotating them helps prolong their life and determines how often needing washing. If after washing, there are still odors that linger then it is time to replace pillows.
First check the label of your pillow to find out if there are any care instructions and what the pillow is filled with so you know how to wash it.
Such as, polyester fiber pillows can be cleaned in a washing machine, while goose down and feather pillows are a little harder to clean but many are still machine washable. Down or feather pillows will break down over many washing and so you will need to either add more down/feathers or replace them. Foam pillows such as Memory Foam should be hand washed and not put in the dryer.
You can wash pillows by hand but it does take more work and time. My tips and instructions are for machine washable pillows.
* Wash pillows without pillowcases or protective coverings on them.
* Fill the washer with HOT water. Hot water kills germs and dust mites.
* Use a mild liquid detergent such as Woolite rather then a powder or other liquid detergents which leave soapy residue behind.
* Place 2 pillows in the washer so that the machine is balanced
* Run through gentle or delicate cycle
* Add 1/4 cup of vinegar to the rinse cycle. It will help with disinfecting and also help remove soapy residue.
* If there is a soapy residue left after the cycles have ended, do one more rinse cycle and that should take care of any soap left.
* If pillows are still extremely wet after cycle is done. Do another spin cycle to help remove the excess water.
* Remove from washing machine and press excess water by placing it between 2 thick towels. Do not twist or wring especially with feather pillows as you will smash not fluff the feathers.
* Place the 2 pillows in the dryer and put on air-dry for feather or down pillows and poly fiber pillows should be on a low-heat setting. The higher heat can cause the pillow filling to clump together. If it is a nice sunny day you can hang outside to dry.
* Stop the dryer every so often to fluff. Or you can put a couple of tennis balls in the dryer to keep the pillows fluffy. Make sure you put each tennis ball into a white tube sock so that the dyes in the tennis ball don't transfer to the pillow. Honestly though I don't like the sound the tennis balls make while in the dryer so I just hand fluff every so often.
IN BETWEEN WASHING
Sometimes the pillows just need a little bit of fluffing between washing. I use a spray bottle filled with equal parts of hot water and vinegar and then 10 to 20 drops of essential oils. I use whatever essential oil I am in the mood for - lavender, tea tree, peppermint, lemon, orange, or rosemary (all of these have disinfecting qualities to them)....usually using a combination of 2. Remove pillow protectors and use spray all over the pillows so that they are fairly saturated. Throw the pillows into the dryer on low-heat setting. Fluffing every so often.