I use Tri-Care Triple Action ointment on most of Huey's cuts and scrapes. It seems to work pretty well and it keeps the flies off of the wound. He gets less scabbing if I use that than he does if I just wash it, and his wounds are healing up pretty fast.
I have a big squirt thing of Banixx on hand in case of big wounds. The SmartPak store is not far from me, and when I went in to stock my first-aid kit for the barn, the women all had praise for the Banixx, and one of them said that she'd been using it heavily on her mare that had a major injury, and it was doing wonders. The nice thing about the Banixx, too, is that you don't have to touch the wound.
I think the proud flesh is a different issue - I haven't had to deal with that yet, but I was reading about it recently, and a lot of people seemed to think that continuing to clean a wound promotes its development. There's a lot of stuff you can find on the web about how to deal with it.
I think the hair grows in white because it is scarred. If you look at pictures of the BLM Mustangs, they're branded, and the hair has grown in white over the brand.