Even more important than curing people would be the requirement to keep my “powers” a closely guarded secret for as long as possible. In the movie, Coffey appears to suffer quite a bit when curing folks. So there would be my own health to consider, but more importantly the deluge of dangers if the word got out. Everything from mobs of desperate people to kidnapping plots by governments. If and when I did perform these “miracles”, I would probably devise some ruse passing myself off as a really good diagnostician rather than a miracle healer. The “cure” would vary with the individual. I would demand that this patient consume a bowl of carrots on the spot, while the next guy might have to drink tumblers of olive oil. I would also swear my “patients” to silence (probably to no avail). The ideal situation would be the ability to cure people without them having a clue that I had anything to do with it.