Ayuh! My daughter suggested it because I'd buy a new one every time mine got stained or dirty from use.
So I placed all my old ones, and the ones all of us are currently using, right into the washer with other clothes, added a color brightener to the wash (I use Vivid), and they came out sparkling clean!!! I was shocked!
I didn't dare put them in the dryer because of their rubber backing so I dried them on top of my dog's crate, but I suppose you can hang them from a hanger with a clothespin to dry.
I am so excited that I don't have to buy new mousepads anymore!
By the way, none of the colors faded in the wash at all - they came out brighter as if brand new.