Apparently it was not considered demonic, he was sought out by JWs from all over. I don't know what his official training was in, maybe as a chiroprator. I never went but many in my KH did. He would have the patient lay on an examining table with just a sheet over them and pass his hands over the person's body, supposedly to pick up heat or energy from the afflicted areas. He never directly touched the person just passed his hands over and over the areas. He would also prescribe things like diet change and drinking fish and olive oils to help pass things like kidney stones.
This was during a time that many JWs were also going to Tijuana Mexico for the Laetrile treatments for cancer, the dubious apricot cure.
A lot of people swore by his methods.