11 years old, peeing in his pants..

I think a mix of negative and positive sanctions might be helpful. I agree with making hard and fast rule about showering every day---well and with soap!---and using deodorant. Withdrawing privileges should be for not following the direction, not just for being smelly.But how about thinking of some positive reinforcement for when he does do it? Some "manly" cologne, many compliments, perhaps snapping a photo of him on a day he looks particularly handsome (and clean)?