Coming from a background of 30 years or more of cycle racing (I am still Secretary of our local club), I wouldn't even consider riding in anything but a decent (not necessarily expensive) pair of cycling shorts with a good synthetic chamois. The things to look for are flush seams at the edges of the chamois - no bits of stitiching that are likely to chafe. Most good shorts now have shaped chamois depending on whether you are male or female (I am female). I don't recommend gel - as this tends to be too thick and can get very hot and uncomfortable on long rides - it feels like a nappy (UK) (or diaper I think you call it). The chamois needs to have reasonable padding but not too much. You want to avoid sore "seat" bones - hence the need for the padding - and NEVER wear underwear under chamois shorts. Make sure too that the leg grippers are not too tight and I can recommend panelled shorts (four, six or eight) rather than tubular legs, they fit better and stretch in the right direction. Look for a high back - the fashionable trend now is for short backs - but these always feel as if they are falling down and will irritate enormously - don't go with fashion, go with tradition. As for washing, I would always try to wash them daily, or at least every other day if possible. It's not necessarily the bacteria that will cause you a problem, but the build up of salt from your sweat - this can cause very nasty chafing which can then become infected by the bacteria and give you saddle boils which will leave you unable to sit for a week. Even the friendly bacteria on your skin's surface will rejoice and happily infect a sore patch of skin that gives them access to nutrient. I am interested to read people's thoughts on shorts for touring because I am fairly new to touring myself, but have ridden very long distances in both training and racing on a daily basis for years - so perhaps it is my race-biased conditioning that is talking here. However, I personally would be scared to death to go without proper padded shorts.