Save you money and skip all the fancy "equine" treatments.
I find that most of the new horses I see tend to have some degree of thrush.
Clean out the location
Rinse it with vinegar or a 50/50 mix of vinegar and water (some people swear by apple cider vinegar and it works fine too, but the only difference I've notice is it make the feet taste better than white vinegar
Wipe down with tea tree oil (apply liberally) daily.
If it's a pocket in the frog (often the case) get some cotton or gauze, soak it with tea tree oil and pack enough into the pocket to fill it. Check it daily to make sure the packing stays. I like to replace it after about 4 or 5 days or sooner if needed. Usually finishes the job in about a week, but I like to do it for couple of weeks just because hate thrush and don't mind overkill.