I have no, not even indirect, knowledge of addiction or rehab facilities, but I do have some experience of different psychotherapy approaches. And I wonder if some of the difficulties in proving actual differences between different approaches might also apply to rehab.
Which in a nutshell, because I can already feel this might be a long post, are that the methods the facility uses and the philosophy they claim to follow are largely irrelevant (as long as they are not provably harmful, which I get is a concern). What makes the difference is mostly the personal connection between the therapist and the patient, mostly the trust.
The awkward phrase "
dodo bird verdict" (all are winners and all must have prizes) summarises the view of some researchers since the 1930s that all therapeutic approaches produce equivalent results.
Of course, there's a lot of pride and money at stake (as with rehab facilities), so lots of talk has gone into proving that one or other school of thought is in fact better. See also
Are all psychological therapies equally effective? Don't ask the dodo | Daniel and Jason Freeman | Science | The Guardian,
Are All Psychotherapies Created Equal? - Scientific American.
Nevertheless, I believe the success or otherwise of a given therapy depends largely on things other than the formal theoretical methods.
Common factors theory - Wikipedia And I suspect the same is true of rehab.
Lot of therapeutic approaches emphasise that the patient ultimately has to take ownership and responsibility, and yet many patients come to therapy because they can't. Isn't this dilemma of willpower also what addiction is all about? So therapy and rehab depend on the patient giving over will and trust to someone else, and then taking it back. The recognition that an addict can't solve their problems themself and needs outside help is the one bit of 12-step programmes that makes any sense to me.
Anyway ... it's a good idea to kick out religious dogma and look for science-based approaches, but I think it unlikely anyone can prove scientifically that one rehab method is significantly better than most others. As long as the place isn't in fact dogmatic and doesn't discard other ideas, and doesn't use guilt and conformity as tools, there might be nothing wrong with it.