Cranberry all the way!

I've had a few of those things and cranberry always helps the most.

Don't bother with the fake ocean spray types of cranberry juices, if you look at the ingredients, there's hardly any actual juice in those at all. Get something that says it actually contains large amounts of real juice in it. I always forego bottled juice and just squish up some cranberries myself, or eat them whole.

Another thing that really helps in terms of cranberry is concentrated cranberry pills that you can get at any health foods store.

I guess if antibiotics are not working properly then all you can do is keep yourself and your shorts as clean as possible, and try some of these hollistic approaches. but I can see how a combination of sweat and things rubbing together might create an attractive home for those horrible little bacteriums!