Brush, brush, brush, brush!!!
Brush that puppy frequently and repeatedly. It helps greatly in dealing with the problem. It stimulates the skin, removes dead tissue and fur, mites, etc...
Thank you for helping out a pup who obviously needs a whole lot of help. I had a chronic mange dog (my first experience with dogs) and we didn't even have ivermectin as a treatment back then. All we could do was give him mitaban dips. It took over four years before his immune system could conquer it. At first, the dips were done every 2 weeks at the vet. After a couple of months when it became obvious Travis was going to be a long-term mange pup, our vet sold us the mitaban and we used it at the first sign of hair loss. When we found him starving and mostly bald at about 6 weeks of age, he looked more like an armadillo than a puppy.
The time between dips increased and Travis ended up being the coolest dog we ever had. He lived for almost 14 years. If you can resign yourself to regular treatment, it just becomes part of normal life. Ivermectin is supposed to be the best thing out there for mange right now, so you're probably stuck with either that or dips for a while longer.
I'm glad you're at least trying. I can't tell you how many people, even vets, will euthanize a chronic mange dog. If the dips and meds keep it under control and the dog isn't going crazy with itching and skin infections, keep on doing what your doing. :-)