How often and how do you wash plastic pants/wraps? My MIL is horrified I don't use a clean pair of plastic pants at each nappy change, but I don't think it's neccessary everytime particularly with just a wet nappy, unless they're dirty imo. I used to put them in with the nappies, but have found that prolonged 60 degree washes tends to shorten their life, so now I prefer to hand wash them in the sink just with warm soapy water. What does everyone else do/think?