Soak him first in some lukewarm water in case he wants a drink, then go for the chlorhexidine soak. Don't want to be ingesting the disinfectant, haha. Yay for clean insides

If you don't have chlorhexidine(www.valleyvet.com), you can go to Walgreens or CVS, even WalMart and buy a bottle of Betadine. Just dilute it with lukewarm water until you get a tea-colored solution. If you have a soft paper towel, you can lightly scrub his belly and the affected areas. Helps the betadine get inside and disinfect everything.

The scale rot should clear up fine in a few sheds. The vet will probably give you some sulfadene creme(burn cream, antibiotic) to put on the affected areas.

Just stick him on newspaper and provide a small water bowl that he can't soak in or dump over. Make sure his temps are a bit higher than normal(I keep mine 94 warm side and 83-84 cool side constantly, and a bit higher if they are a rescue battling an illness). Higher temps will help his immune system and help him heal faster.

Hope that helps!