Back when demodectic mange was being discussed, I asked my daughter what
she could tell me about treatment of this problem.  Several years ago,
my daughter worked for a county humane society.  They had taken several
dogs from an out-of-State rescue that had more dogs than they could
handle.  One of the dogs was in very bad shape.  It suffered from
demodectic mange and did not respond to treatment.  One of the vets
eventually decided to put it down.  My daughter proposed taking the dog
home and treating it herself, and that's what she did.  The dog, by the
way, is a tall, skinny female named Sally that looks like she might be
part Doberman and part hound.

My daughter is a very busy person and often takes a while to answer her
e-mail, but today I got her reply, and I'd like to share it:

For Sally I tried everything.   We started treating her when she was
just shy of 4 months old.  First, we tried dipping her every other week
with Amitraz and washing her with Pyoben shampoo.   That did not seem to
work at all, so then we tried oral Ivermectin daily for 3 months ( You
cannot do the dip in conjunction with the Ivermetin because they are
both MAOIs, and it could cause severe neurological damage).  The
Ivermectin seemed to control the mange, or kept it from spreading, but
it did not get rid of it.  I also started giving her all kinds of
supplements, including Vit E, zinc, Vit C Selenium, Sulphur tablets, to
relieve the itching, a mixture called Healthy Power, which I found in
Dr. Pitcairn's Natural Health for Dogs and Cats. immune liquid, which I
found at an all natural pet store, flaxseed oil, all-natural pet food,
and Amoxicillin, to clear up the secondary skin infection.  After 3
months on the Ivermectin, Sally went blind, which is a possible side
effect that none of the doctors were aware of.  I immediately took her
off of the ivermectin and her vision came back after a few days.  So, I
stuck with all the supplements, and by the time she turned 1 year old,
she was mange free.  So, I don't know if it was the supplements that
helped, or if her immune system had just finally developed enough to
kick the mange on her own.  If I had to do it all over again, I would
probably start with the supplements, and see how that worked.  I don't
think that I would ever use the Ivermectin or the Amitraz dips again.
One of the vets that I worked with had a dog, the same age as Sally, but
his mange was never as bad as Sally's-  He mainly has it around his eyes
and on his feet.  She put him and Interceptor-   He was on that for a
long time, and I guess it worked- Very expensive though, but I think it
would be worth it is it worked.  It's gard to say if the various
treatments work, or if the dogs' immune system just develop and they get
rid of it on their own.  All the dogs that I have know with mange were
shelter dogs, and I'm sure got mange due to their extremely stressful
environment.  After being in a home, and getting rid of that stess, one
would think that the dog's immune system would take over and control the
mange.