Treating Persistent Mange?

My mom's Dalmatian got mange from a kennel while on vacation. He always gets very itchy in the month of October every year with allergies, but this year was prolonged and was so bad he was scratching the skin off his face even while taking Benadryl.

After many trips to the vet, receiving steroid injections, antibiotics, and more steroid pills he has finally been diagnosed with mange. He is being treated for it now, but the 48 hours that we were told he would find relief are up and he is still miserable and scratching like crazy. I'm afraid its going to kill him with depression. The poor thing has his party almost all day everyday.

I am looking for some kind of home remedy that will help with the worst areas being on his face (eyes and mouth are the worst). I see many things on this site, but don't know which one would be best with it being on his face. This has been a 2 month on going problem and we need help fast and don't seem to getting it from the vet!