Thrush Buster is very effective. It is very important to keep the area clean, keeping it clean exposes the fungal infection to air and air will dry it out and heal it. Your farrier will be able to trim the area to help with this. Depending on the area, I would also invest in some Q-tips to clean out small spaces.
I also use rubbing alcohol to really dry up the foot.
I use Thrush Buster as well and find that it works great. When I first started using it, I used it probably twice the first week simply because my gelding had a bad infection. After the first week, I went back to the once a week preventative as a safety precaution since he enjoys standing in the creek while grazing the grass along the edges... It seems to have worked pretty well so far. Whenever he has a little pop up, I hit it with the thrush buster and it goes away.
Another option that seemed to work good was Thrush Remedy. I borrowed that before I got the Thrush Buster and then switched once I got my own stuff. With Thrush Remedy, you have to treat over a course of 3-5 days until it is all gone.
My trainer and other riders at the barn use Thrush buster, so I assume that it is effective. But what's also helpful is to prevent thrush in the first place - pick your horse's feet the first chance you get when you arrive at the barn, pick them before and after a ride, and pick them if they've been standing/walking in shavings, mud, etc. - pretty much just pick a horse's hooves every time you can! It's really helpful in preventing thrush. Also, keep your horse's stall/paddock/pasture free of manure, mud and water. Hope this helps!
I have used copertox (spell?) I packed cotton down in the crack of the frog where the thrush was and soaked it with that stuff. I treated him every couple days and gone within 2 weeks. The best part was, I didnt have to treat everyday. It really was not a big deal at all. I have also heard thrush buster is great too but I think copertox is a little stronger. Good luck!
Thrush buster is number one, bleach and water is second best. Bleach and water is cheap and easy to find in case you are ever in a hurry. Picking your horses feet twice a day and picking all the black out will help, then apply the solution. Keep your horse's feet dry as possible.
My farrier told me to get bovine mastitis treatment, which comes in tubes like wormer, and squirt that in a couple times a day. It worked fine. You can buy it at places like TSC, and it's pretty cheap.