All I can tell you is this, from my own experience. My first husband and I were dating, and had been going round and round with the alcohol issure for quite awhile. He was 21, I was a couple of years older. A co-worker gave me a copy of the BB. I read the book and gave it to him. He thought it was interesting, wanted to try on his own to quit.
Of course, that didn't work out, so he finally agreed to go to an AA meeting (I went with him). He thought the people were nice, but he still thought he could do it himself.
A few months later, I was at the end of my rope, and I said, "I need to take a break from this because it is making me crazy. I want us to not see each other for awhile. Maybe we will get back together, maybe not, but I can't take this right now."
A short time later he went, on his own, to an AA meeting. He never drank again, and that was 31 years ago.
OTOH, my second husband went back to drinking shortly after our marriage (we married during a sober interval, when he was in AA and I was overly optimistic because of my first husband's success). Number two (lol, no pun intended) is still, to this day, I believe, drinking himself to death (he'd almost died of liver failure before we got married).
So. Apparently my first husband was ready to stop destroying himself, my second husband was not. *shrug* I don't think there was anything magical I did, either time, with the possible exception of handing the BB to my first husband, who was ready to hear the message of hope.
Alcoholics have totally screwed up thinking. When we are drinking, we can see no way out, no way we can imagine living without alcohol. It has us tightly around the throat. People can tell us what to do to recover, but until we are desperate enough to do ANYTHING to make it stop, it's really just going to go in one ear and out the other. All we can see is that alcohol seems necessary for survival. And anyone who interferes in that gets resented and blamed. It is neither fair, nor reasonable, but it is a fact.
If I were you, I would operate on the assumption, until and unless proven otherwise, that he is not presently at the point where he wants to be sober more than he wants to continue to drink.