If you can get a product called Vetericyn, that would be an excellent thing to use. I don't want to sound like an advert, but the stuff is great. I am in no way associated with the product or paid to use it ... but it's amazing.
I have used it on my dogs, horses, and cats. Saved me A LOT of money on vet bills, especially for hot spots, cat bites (prevented several abscesses), and even a poison oak rash on my dog's chest. Sprayed the product for a few days and it was gone. Used it on my horses legs when he developed some scabbing rash down on his fetlock. Sprayed it 2-3 times a day for a few days and it was gone. My mare had a terrible rub mark on her face and I thought she'd have a scar ... sprayed Vetericyn on it for a few days and it is no longer there and all the fur is back. I am a skeptical person, but I got a free sample at a horse clinic and first used it on a stray dog that had a mauled ear that crawled up on door at something like 2 AM on a Saturday. I cleaned it with cotton and Vetericyn, and then I sprayed the Vetericyn on it for a few days while the animal rescue tried to vet her (animals always get hurt on the weekend when no one's around). Her ear was DISGUSTING when she came, oozing and awful, just a real mess. I was pretty sure she would need massive penecillin and some stitches, but no, she didn't. The resuce vet actually called me to ask what I had used on her because it worked so well - her ear was almost totally healed when they finally were able to vet her. I have the product in my barn all the time now. To be honest, at this point I would be surprised if it DIDN'T work on some sort of rash, rub, cut or burn (I used it on myself for a burn and it healed right up, but it does say "Not Approved For Humans" - my girlfriend's son uses it on his acne and it works on that, too, amazingly enough). If it didn't heal Sweet Itch, I'd be shocked.
It's not cheap, but it totally works.