Maybe a bit off topic but I'm going to throw this out there anyhow. Perhaps someone can offer a suggestion.

Because of back problems and fibromyalgia I sleep with this huge U shaped body pillow at night. I wash the pillow cases frequently but the problem is the pillow itself develops yellow stains (sweat maybe?). It barely fits in the wash machine and when I do that I risk damaging it. I'm actually on my second pillow because the first one tore in the wash machine. And it's not a cheap item! I wish I could get a plastic protector like you can get for regular bed pillows but there is no such thing I am aware of.

Any thoughts maybe on spot cleaning it?

Here's the pillow.