Originally Posted by littlemissmuffet:
Dump them in a sink/tub/container of water/bleach solution and start scrubbing with a scrubby brush. Rinse. Let dry on a towel overnight.
This is what I do. I've never had them change color though. I do it whenever they are out (they are a 'once in a while' toy') because the younger ones always seem to have them in their mouths.