An ultimatum might be considered the final boundary. I felt like it was only fair to let my alcoholic husband know I was considering leaving because of the drinking. I let him know a couple of times that I was reaching my limit of tolerance for the drinking, and if it continued then I would leave. Finally, I told him that the next time it happened I would leave, and I followed through on that. (I didn't say that until all my preparations were in place so I could leave promptly).
Did it "work"? Sure did, I got myself out of the situation with a minimum of tears and drama. I felt like I'd given him every chance to choose recovery, I'd waited long enough that I was satisfied he simply wasn't ready to quit. And there wasn't a big nasty fight, I just quietly left with my stuff (I'd already removed my most precious possessions and irreplaceable papers). I didn't divorce him immediately, but when it made sense to me to do it (he was talking about leaving the country to live with a sister in Africa), I did it.