One thing you will find here is honesty. We have no reason to lie or give bad advice. Coming from a family touched by so much alcoholism, you know that an alcoholic/addict will not stop until they are done. Nothing you or you husband say or do will make that happen. He has to find his own bottom and from everything you have said, he does not appear to even be looking for it.
Many of us have had to walk away from loved ones who continue to make bad choices. When those choices begin to affect our lives, we have to save ourselves and let the addict figure things out for themselves. Again, your friend knows what to do, he just doesn't want to do it.