This might not be very helpful but just in case here goes. We used to board with a lady who showed dogs. She told us about a product they use on dogs with long hair that they simply called "stuff". It also works great on horse mane and tails to detangle and shine. We've been using it for years with no ill effects. My sister gets it from the same lady and still doesn't know what it's really called--lol! I mostly just use Cowboy Magic to get the knots out--works wonders and smells good too.
Horses are proof that God wants us to be happy