I just posted this on another thread, but I'll say it again:
Try pine tar to cure your thrush or abcesses. You just pick the hoof out, take a stiff brush over it to get everything off, and then apply the pine tar thickly to the bottom of the entire hoof. It won't hurt anyone, so if you get it anywhere else, or even on yourself, don't worry. It's just sticky, and hard to clean off. Then carefully place the pine tar coated hoof in a fresh pile of sawdust and pack it in. Allow the horse to put his full weight on the hoof, but try not to let him move. Do that for all 4 feet.
In the past, I've only had to do this for 3-4 days before clearing everything up. The sawdust pad will fall out, so you have to replace it every day. The pine tar seals in moisture, but sucks out the abcess "gunk". Provided your horse isn't wading in manure everyday, you should be good after a week. Not knowing the severity of your horse, it could take longer, but this is definitely a good place to start. The main ingredient of most thrush cures contains pine tar, but not in large enough doses sometimes. I'd give it a try. I have always done this with my horses, and it works everytime.