Yes, it's called "Shapeley's MTG" and sells for around $4 for a sample sized bottle at TSC. Here's what I did:
Day 1: (In the evening) Soak in warm water to loosen any dirt/scabs that can come off without too much irritation. Dry as thoroughly as possible, let him/her stand in a clean, dry place to air out a minute. Then I shook the bottle really good, and applied directly and generously all over the affected area, massaging into the skin/scabs. Wash your hands good afterwards, 'cause it stinks!
Day 2, and every evening thereafter: Shake the bottle, apply directly to affected area, gently rubbing off any loosened scabs, and massaging the MTG into the affected area. Don't worry about washing/soaking or excessive picking off of the scabs...they'll come off when they're ready. I brought my horse into a short grass paddock for each night, just to prevent the heavy dew on the thicker pasture from pestering it.
If my horse is any indication (and I've read some similar testimonials) you should see improvement right from day 2, and a huge improvement by day 4. I found that no new scabs formed, and the skin was pretty healed on most areas by day 3.
If you try this, please post here! I'd love to hear if it works for you too.