Simple. Buy more shorts. Wash as needed to ensure you always wear a clean pair. I -never- ride with a pair of shorts twice before washing them. Absolutely never. I guess I have about 5 pair of shorts and after I'm down to 2 pair or so I make sure the others are washed. I also never ride without showering that day at some point before going and after I get back from a ride I shower. Sometimes I just wash up but the key is to keep clean and upon returning, clean and dry.