I believe that a horse that learns to pull back will continue to do it if you don't fix it right away. I always use a really good (hamiltons are great) halter and a heavy lead with brass snap. I take them out and tie them to a tree and walk away. Grab a drink and a chair and watch the show. I have never had any injury worse than a couple scuffs. The tree of wisdom works on all ages and you rarely have to do it more than a few times. Make sure you leave the horse there for an hour+. I have found that rope halters are a bitch to get off after they have been pulled on, but they do work for a horse that doesn't fight to hard. I also found that the "let the rope just slip off" method doesn't work on a lot of horses. They just continue to pull when actually tied. If the horse is a real fighter, I might use a neck rope. I use a real neck rope that can not slip or tighten on their neck. We deal with a LOT of "problem" horses and this method is by far the best permanent fix we have found.

NOTE: Use a tree that you don't care if it dies. They may tear it up pretty good.