This is a really tough situation and I'm sorry for what it's putting you all through, especially the kids. Don't think I need to point out again that you didn't force her to drink, and she didn't force you to have an affair and that two wrongs don't make a right.
What's done is done. For some people, addiction is a deal breaker and for others infidelity is a deal breaker. Yes, the marriage is in big trouble, but it sounds like it has already been in big trouble...that can often lead to affairs and addictions. Can it be repaired and to what lengths are you willing to go to? Do you want to save your marriage? I personally believe that if two people have a strong desire to mend the wounds and get help, it can be done. Gonna take a whole lot of forgiveness on both your parts as forgiveness is needed to heal those wounds. I wish you both the best. Hang in there...
It is tempting to want to 'get back' at people who have hurt us and to want to have some control because we seem to think that if we can 'control it' we can stop bad things from happening again. Making her watch a video that would only bring more pain to her I think is your way of somehow proving a point and perhaps a bit spiteful and doesn't really do anything to heal the wounds.
You've BOTH got to think in terms of what it's going to take to heal the wounds.