For hot spots I recently read something about DMSO curing them so I mixed up a solution of 1/4 cup water, 1/4 cup apple cider vinegar (with the mother), and a scant 1/2 cup 99.9% pure DMSO I got from the county coop (I've also seen it in horse supply shops). I used a small spray bottle to apply it to the hot spots that had my little beagle acting like he was 90 years old, using the bottom of the bottle to brush the hair forward and expose the spot better and then using the same bottom to rub the solution into the skin. He doesnt like the process and immediately tries to lick it off but this old dog is now acting like an energetic happy puppy again. I try to distract him with a few treats or walking after treating him so the solution has a chance to soak in. I apply it three times a day and in four days after starting he already has hair growing back into the area again.
I believe this solution would work for a cat also in that all of the ingredients have been used on cats with benefit whereas many natural products can harm a cat since their liver can't process some things like a human or dog can. DMSO doesn't smell good but is preferable to watching your dog/cat suffer and/or spending lots of money on ineffective things from the vet and the scent doesn't last all that long.