5. Reapply as needed. For example, when drying sweat, some spots might have more moisture. Go ahead and use a little, repeating steps 1-4 to help soak it up. But if you're using this to treat rain rot, and some scabs still remain on the skin, use a bit more to help remove them. Any extra powder that remains will only help prevent bacteria and fungus, all while keeping your horse's coat clean!