In a way it is difficult to answer your question directly since he has already done both rehab and AA.FYI, I come at this from both sides - as someone who is recovery for alcoholism (18 years); a history of being in relationships with people who for a variety of reasons can't/won't get there and many years of working with people who can and do get there. I went to rehab,followed by years of involvement in AA. I don't know which one worked the most....I do know that so I wanted to be free of my addiction that I would do whatever it took,whatever other people who had been there and found a way to get and stay sober told me to do. I decided to get out of my own way because my way got me precisely nowhere.
I went to rehab and was told by my counselor there that she thought I would be one of the one's who would make it because I did what I was told to do,whether or not it made sense to me. Most adults don't like to be told what to do. Addicts REALLY don't like to be told what to do!! Most of us are very emotionally immature. We are the definition of wanting what we want when we want it!! and we want it NOW! like a 2 year old.
I believe that statistically one's best shot is to go to rehab followed by deep involvement in AA (rehab buys you time away to get some clarity but it's also all about starting in AA and being told to continue once you get out). In lots of ways they are the same thing.....in the end it is about a person's individual desire and commitment to get and stay sober. It isn't rocket science and there isn't any magic to it. It is really very simple,though far from easy. As they say in 'the rooms' "it works if you WORK it" and believe me it IS hard work,especially the first couple of years. Most things worth having are.
For someone like this person who has already been in rehab-more than once-treats AA like it has a revolving door etc. the problem isn't the program.The problem is the person. He already knows what to do. He has been told 8 zillion times. Basically he either hasn't wanted to do what he has been told to do or perhaps is not capable of the kind of 'rigorous honesty' that is necessary to succeed. Maybe he needs more pain. Who knows? I do know that asking a nonalcoholic (like you) what you think he should do would be like me asking my manicurist how to treat my stage 4 cancer (also known as going to the hardware store to buy milk). Think about it ...... if you are not an alcoholic or someone trained in addictions how would you know what he should do? He knows perfectly well that he can go to an AA meeting ,ask for phone numbers and call and ask recovering alcoholics what to do/what they did. That is how the whole thing works. Problem is that we recovering alcoholics are not nearly so 'understanding' as the kindhearted non-alcoholic that a active alcoholic is inevitably manipulating. We might say some stuff he doesn't want to hear because we see right through all the BS!
Better to chat with you about it than make THAT call!
I honestly don't think that repeat stays in rehab are of much use. It is my observation that people who do multiple rehab things do so to convince the people around them that they are 'serious' THIS time. They are the most annoying of the other patients in rehab...because they haven't learned to 'walk the walk' but have learned to 'talk the talk'. They haven't learned in their previous stays how stay sober...they've learned how to 'do rehab'. As in all things,I am sure there are exceptions. I can tell you that when I come across someone like this in AA (and there are more than a few) I do not go out of my way to help them until I see them really committed to shut up,listen,follow suggestions and start working hard.
IMHO the best thing you can do is step back, get some help for yourself to understand this disease and observe what he chooses to do. What to do about his addiction and where to go to get help is HIS problem to solve. He knows what to do. Now he just has to do it. Recovery is Nike time "Just DO it."
I go to both AA and Al-anon. I find dealing with other people's addictions far harder than dealing with my own. I have control over my own choices. None over other people's. Addictions are horrible and heartbreaking. The person with the addiction gets to 'check out'....we get to feel all the pain. I feel for you. Been there. More than once.
I have no answers.Only observations/opinions/suggestions based on my own life's journey.TWYWLR