The pillow collects a lot of dust, skin cells and bacteria that need to be washed out. Fortunately, most pillows require washers and dryers.
When cleaning other parts of the house, pillows are easily forgotten. Just because you changed the pillowcase does not mean that the pillow is clean. Due to dust, sweat, dead skin cells, mold, bacteria and other accumulated allergens, the weight of the pillow can actually double over its entire life cycle. (Pooh!)
How to quickly test whether your pillow is worth fishing: fold the pillow in half. If it does not rebound immediately, it is best to put down the pillow and buy a new pillow. If it bounces back with a bit of anger, it's still inside and throws it into the washing machine.
If the pillow is filled with feathers, down or polyester, then you can put it in the washing machine. Clean two each time to avoid machine imbalance. Air is squeezed out as much as possible before putting it into the machine. Use hot water and a mild natural detergent. Add a glass of baking soda or white vinegar for mold and mold.