Here is Buddy Underwood's website. Check out the 'testimonials page' and look at the actual pictures. I have seen some even worse than these.
Underwood Horse Medicine - Wynnewood Oklahoma
We have known Buddy for years -- he lives a few miles from us. I have seen some of the horses that the Vets wanted to put down and people healed them up with this stuff. The Vets around here recommend it for flesh wounds and huge skin tears. I have seen horses that had shredded the skin and muscles across their chests and forearms. The skin and hunks of skin and muscle hung down past their knees and this stuff healed them up -- with no infection and no flies in the middle of the summer.
I am using it on one right now that another horse chased over a fence in a corner. It was not a barbed wire fence, but it laid all of the skin on one shoulder down a foot or more. It is just about healed up and the gap is down to about 2 inches. It started out about 8 - 10 inches apart.