I have never had good results with it and it stinks and stains. Although never had cats only dogs that I used it on. I always shave the hot spot, soak off any scabbing with a warm rag and then treat several times a day with a Chlorhexaderm solution then after that dries I apply Betagen Spray which is an antibiotic. Towards the end of the healing I apply Neosporin and they heal up really fast. If you keep the Chlorahexiderm solution handy and keep a watch out for the beginnings of a hot spot you can treat the area with the solutoin and prevent a full out hot spot and not have to shave the area. I keep a spray bottle handy and if I notice an area that has hot spot potential I soak it a few times a day untill it is gone. Works for my dogs ;)
I prefur to have my Bordeaux with fur instead of a cork and bottle ;)
Neosporin works wonders on hotspots, but you have to keep the treated animal from licking the spots. If your cat has fleas so bad it has hot spots, you have to treat the source of the fleas, not just the results.
Never trust a tall dwarf... he's lying about something.
Be careful using sulfadene as kicks lick most everything you put on them. Chlorhexadine is good and if worse comes to worse the cat may need "a collar" to prevent him/her from getting to that area. The other thing is, why is the cat licking?