I used Chamois butt'r on a tour last year. I rubbed it onto the shorts specifically where there were seams and if the thread had been doubled back. I didn't have any issues at all on that long ride. I don't generally use it on a weekend ride unless I have been riding a lot and feel some chafing coming on... an aside, I don't generally have infection issues, so I may not be the best resource here. Also, I made a point of changing out of my shorts just about the second I stopped riding on that tour (this was on the advice of a more experienced touring girlfriend of mine).