If they can take it, soak them in regular white vinegar and then rinse them off with hot water. I even use vinegar to clean my aquariums. It works wonders!
I second the vinegar! The smell goes away pretty quick after rinsing, and it's safe for everything. You can soak the hide in a tub or put some in a spray bottle if it can't be submerged. Some even say it's a better cleaner than bleach!