text: how do i get the taste of soap out of plastic mouthguard? i am using a molded plastic night mouth guard and i stored it in with my bathroom supplies and now it tastes like soap. i have tried soaking it in denture cleaner as well as rinsing it with extremely hot water (which really isn't that good for it). i have to get this taste out as this is a $600 appliance and i don't have the money to replace it. soak it in either lemon juice or in white vinegar.  zaps the other tastes right out of the plastic.