A common remedy for a dry skin condition is evening primrose oil, one teaspoon mixed in a dog food. A dog's skin falling off is often insects, but can be certain staph bacteria for example. As an emeergency remedy I used, milk of magnesia (no aluminum) mixed with water at a ratio of about 1: 2 (which means one part water two parts milk of magnesia solution). The milk of magnesia kills off the invading staph and other bacteria whenever H2O2 and Borax fails to work. As a warning, the milk of magnesia may cause the dog to have a mild diarrhea, but it seems to help some detox. A baking soda 1/2 teaspoon per liter of water will help raise the dog's immune system. On the other hand 1/8 teaspoon only once a week of borax mixed in one liter of drinking water will help the dog raise the hormones.
As to other remedies that may help, the opening of wounds can be healed faster, some aloe vera is applied or in some cases that has helped me was the application of milk of magnesia, than this is followed by a vaseline to prevent further infection in case things do not work out.
In some cases a certain mange can be resistant to H2O2 and borax treatment due to a REINFECTION. If this is the case the H2O2 and borax is redone, but this time the dog is quarantined in a small room or cage that is sterilized and clean during the treatment period. I have found this method to work quite well in case the H2O2 and borax didn't work initially. I suspect that there is a small hives of mange somewhere in the house that the dogs get reinfected, and hence a quarantine the dog in a clean sterilized area, instead of allowing the dogs to roam around a large area seems to do the trick.