I would second what atalose said--I know that I certainly thought that there was some switch in XAH's brain that snapped back to "normal" once the alcohol was out of his system. I saw it as some sort of Jekyll and Hyde thing, but that is not the case. The alcoholism, and all the attitudes, thought patterns, deceit, and so on that goes with it, doesn't instantly and completely vanish just b/c he hasn't had a drink in the last 12 hours. That's why recovery is a long process involving a lot of hard work, not something that just happens after a few days w/o alcohol.
I imagine you're putting a lot of weight and expectations on this "big talk." I know I always did. And all I ever got was denial, false promises, and talk that made no sense at all. He claimed to not understand why I'd be hurt by his lying. He claimed to not see why I cared if he was drunk every night, saying "I'm still the same person", claiming he acted and thought the same way, drunk or sober. (Sadly, there turned out to be more truth in that statement than I would have ever believed...)
I understand your need to do this, b/c I was there so many times myself and had the same hopes. Just try to bear in mind what folks have said in this thread, OK?