So what's a guy (or gal for that matter) to do on race day when weather is imminent or you are going to sweet like a stuck pig and you know things are going to rub? You reach for some kind of lubricant, much like greasing up parts on your car because metal rubbing against metal for too long might cause some fire.
Body Glide. This stuff is amazing. On my longer races and runs (anything over 15 miles) especially if wet crossings were involved, I almost always had some hot-spots form on the bottom of my feet due to what I term pruning of the skin. If it started raining, I would chafe in other places. It was almost a sure fire bet I was going to chafe and blister if I did a 50k. With Body glide, I reduced that likely hood dramatically.
My last 50k was War at Windrock the first weekend in April. After about 5 miles in, my feet were soaked and stayed that way throughout the rest of the race. Prior to the race, I applied the Body Glide to the bottoms of my feet, liberally around the toes and balls of the feet. Also on my nipples, between my thighs and other areas that I would normally chafe. Once done, I added it to my drop bag which would be available to me at the 20 mile point.
As I said, my feet stayed soaked, and my boneheaded self decided not to change socks or reapply the Body Glide to my feet. Regardless of that, I still ended up with one blister on the ball of one foot and another blister on my 4th toe on the other foot. I can easily say that if it weren't for the Body Glide, my feet would have been in a lot worse shape. Thankfully, everywhere else I applied it came away from the 50k chafe free.
A little bit about Body Glide directly from their website: (http://www.bodyglide.com/products/original/)