I'm not an expert on hotspots, but I generally clip away hair if necessary, clean the area with hydrogen peroxide (which also helps the hot spot dry out), pat it dry & then powder with Neo-Predef with Tetracaine Powder (ingredients: neomycin sulfate, isoflupredone acetate, & tetracaine HCl)from the vet. If on the leg, I usually try (sock or huge piece of gauze) to loosely cover the area. If the hot spot is from scratching, I'll frequently "double sock" the offending scratcher. Hope that helps someone!
Fidele, Belle & Cedar

I have had luck with cleaning the hot spot and cutting away hair, then applying a mixture of cortisone cream mixed with Neosporin w/PAIN RELIEF.
After applying, we watch her closely for about 1/2 hour, by then the Neosporin has numbed the area and then we put a sock or gauze pad on. Usually have to do this 2-3x a day. The cortisone helps heal and the Neosporin relieves itching. Works pretty good unless hot spot is severe and it is amazing how quickly they can get bad. Good luck