
When it comes to whether down pillows can be washed, a widespread myth is that washing can harm the feathers and down inside the cushion. Down pillows, on the other hand, require regular cleaning for textile protection and dust mite management. According to the International Down and Feather Testing Laboratory, down can be washed without causing damage if the proper process is used. In fact, improperly washed down pillows can serve as a breeding ground for dust mites.
According to EPA data, the human body sheds roughly 1.5 grams of skin cells per night, providing adequate food for dust mites. Dust mites are a prevalent cause of allergies and asthma, and regular pillow cleaning can significantly reduce their population.
As a result, the proper statement is: Down pillows can and should be washed, but certain preparations and safeguards must be taken. Incorrect washing procedures may damage the pillow's fillings or cause mold to grow inside the pillow. I hope that this scientific theory and data support can dispel your worries and convince you of the need to wash down pillows.
Cleaning down pillows every 6 to 12 months is generally suggested. Regular cleaning aids in the preservation of their fluffiness and hygiene. However, excessive washing can harm the feathers and result in scant fabric shells, making it easier for feathers to escape.

—Washing Down Pillows by Hand.
—How to Dry Down Pillows Properly After Hand Washing.
Tip: It takes at least 5 days for an undried pillow to air dry. The top may feel dry, but the inside filling may not be totally dry. You can tell if a pillow is dry by its weight; a wet pillow will be slightly heavier than usual.