What about ButtShield? I have not used it, specifically, but I use SportShield for inner-thigh rubbing and spots that tend to rub on the back of my sports bra when I run...it works amazingly well for hot spots like that. I think I may end up with a spot on the back of my right butt cheek with my Bontrager InForm saddle--but it's the ONLY saddle I have found that doesn't rub my girl parts raw, so I can deal. I use their BlisterShield powder in my socks for long runs, too (and under my Superfeet insoles if they squeak in my shoes).