I've used a LOT of Body Glide. Tried similar products and have come to prefer Gold Bond's Friction Defense.

Hiking (not backpacking) have found there's no protection for my "firehelmet" without underwear. Just a reality.

Prefer the new poly compression undies too. Wore them under my kilt on my Grand Canyon raft trip and became a believer.

Something that hasn't been mentioned yet is I've also had the back of my knees beaten raw by the hem of both wool kilts and cotton Utilikilts. Worse if the kilt gets wet.