I know this is an older post and not sure if you had your issue resolved.
For thrush, I use Destin Maximum. It works great!! Vet and Farrier said it should work fine, but if it doesn’t, let them know. You only need to use 2-3 times per week with Maximum. If you use the regular, you’ll have to apply everyday. I soak, clean and dry the hoofs then put Desitin over the entire bottom of the hoof and in the sulcus or any other cracks in the frog and on the heel bulb. Sometimes he hates me soaking them and can’t get it perfectly clean, but it’s never been an issue. As another poster said, Vinegar works great also. I poor into my water when soaking.
For hoof wall repair, I have used Absorbine Hooflex Conditioner Liquid. You only need to use this once per week, but you can use this more often as needed. A little goes a long way. You may see a difference within a week. I use Desitin and Hooflex together. I spread the Hooflex (has an attached brush) over the entire hoof… from frog up to coronet band.
I was told thrush and scratches are caused from moistness. Since I moved my horse from my old boarder to home, my horse has not had scratches at all and thrush is minimal. Ground is more wet here than there. So I’m not 100% sure it was the moistness and may have other factors at play. Good luck with the thrush and the hoof crack.