Given the nature of AA, a lot will depend on how both the numerator and denominator are defined. Many people will come for a meeting or two and aren't even seen again. Is that person counted as a participant in AA? And what does it mean for AA to work - don't ever drink again? Etc. It's part of the reason there are no good stats that I've seen. It's probably lower than the AA touted number of around 40%, but IME far higher than 3%.
FWIW, I fully support any approach that works. AA is sort of polarizing. Many AA folks are zealots for AA and scoff at alternatives, and there are a number of people who are vehemently opposed to AA. To me it's like taking a hard line position on weight loss, or 'fitness.' Some methods work well for some people and fail others miserably. Whatever it takes is great with me, and in the meantime there are many thousands in AA living pretty good lives sober. That's a good thing.