MicahMI know this question was from four years ago but I wanted to answer the question for anyone else looking for an answer regarding machine-washing.
I wash mine by itself on a gentle cycle with cold water and a tiny drop of detergent and then air dry it. I've never had any issues with it.
Granted, I have an older washing machine and I can't speak to all models so it may vary some in that regard.
There is a comment from sneakeyboard that has info on how to hand wash.