I'll suspend judgment on this one. I don't see any signs that these people are invoking spirits or demons. And some of these "alternative" methods seem to work, acupuncture being the best known example. Herbal lore also can be beneficial, although few MDs know much about it.
If so, then there's nothing religious about it, one way or the other. It's only troublesome because it seems to be spreading among whacky nuns, if this story is to be believed.
Yes, it could become dangerous if it has a false religious element, but I'm not sure that's the case.
I've done both: accupuncture and herbs. My screen name is from an herb I took.