I used AlAnon when I was not really in a situation where I could leave - I was merely coping.
When I left. (Or rather, he left), I used NC to try to sort out what I wanted. It was my version of "needing space." And I used it to discover "me" and what I really wanted.
I thought it was very helpful for where I was, just as I found AlAnon very helpful at a different time.