Well, say you had some emotional issues or. . .
. . your life seemed without direction. Would you go to a psychiatrist and expect "scientifically verified" results? From the results I've seen you won't do any worse with your local witch doctor, and it'll cost you a hell of a lot less - and if s/he's good it just might help.
For a chronic health issue where the doctors simply say "there's nothing wrong with you" or go wandering off on some currently popular but inappropriate tangent as they often do, a healer is probably a better choice - at the least less damage will be done.
Here again, effectiveness is an entirely personal thing, a relationship between the practitioner and the client. It's up to the client to judge if that relationship is effective.
Practitioners that try to be "scientific" are generally ineffective. Back around 1970, Paula, a former girlfriend, was taking singing lessons from a well known teacher, a Dr. Long, who was also president of the American Astrological Society.
The AAS was trying to get a law passed in California to certify and license astrologers. Certification was, of course, to be according to the "scientific" astrological principles of the AAS.
Paula was sent out on spying missions to various astrologers to have readings done and report back as to their compliance or non-compliance. She told me that what really struck her was that the really good ones paid no heed to "scientific" principles at all, but used the tools in their own personal way, and each in a different way. Those that followed the formal rules were all hacks.
Phrenology is a pseudo-science and unlikely to be effective in any way - but the Wiccan crystal goddess might be effective, and at least will be a lot more fun, and that could help right there.
A funny: - Years ago I was at a party talking to a schoolteacher. She told me that the year before she'd been at some sort of teacher's retreat. A card reader had set up camp there and did readings between scheduled events.
She told me that several teachers had readings done and were urging her to have one, "It's fun!". She told them it was senseless and irrational and she wouldn't do it.
Finally succumbing to peer pressure she sat down for a reading. The guy spread the cards and looked at them for a bit, then looked her in the eye and said, "First of all, you've got to stop messing around with the guys at work".
She told me, "That hit so hard I didn't hear another word he said".
