It "doesn't work" because it isn't repeatable or predictable. My wife has a similar story to yours... I had a zero effect experience with the same practitioner.

Like chiropractic, there is "something" there, but it's mostly mild physical relief + belief/placebo effect.

That's not necessarily a bad thing, especially for pain relief where the alternatives are pretty high impact (surgery, ineffective narcotics, other treatments that lose efficiency over time). The problem is there are practitioners who claim to cure cancer, etc, and there's no way for anyone to vet that.