Prior to the "Get Selected" book coming out (Outstanding job sir and MSG), I did my own research on blisters for about 2 and a half weeks. One source talked about the only solution he found for blisters was to put duct tape on his feet where a hot spot would build up. I questioned some medical personel about this and they said it was not advisable as the feet didn't breathe. I figured they never humped a ruck except in Basic, so I would take it with a grain of salt.
Prior to my ankle injury, I was rucking 2-3 times a week with minimum distances of 5 miles and go out to 14+.

My feet eventually toughened (now softened up like daisies),

but I tried the duct tape method when I hit hot spots and blisters. Duct tape worked like a charm and allowed me to move out like a herd of buffalo for miles and miles.
I noticed in "Get Selected" duct tape was not even mentioned. Any advice and insight is always appreciated.
SS