After XAH fell off the wagon after his 1st big (60day) inpatient stay... or maybe it was just that I thought he had but he hadn't admitted it (I don't really remember), but I decided I was tired of the advances, tired of the smell, tired of everything. My marriage was pretty much over, but he didn't recognize it.
The tension just got to be too great, and one night I declared a moratorium on sex. Just like that - and I even said it that way. I wanted to be perfectly clear that I wasn't interested, and to not bother. And until things improved, I wasn't going to be interested.
I figure it was sort of like how the UN imposes sanctions on a rogue nation. I had enough power in the relationship (he was never abusive) to just state my intentions, and I stuck to them. Getting it out in the open helped, but then again, I knew my marriage was over and it was only a matter of time.
FWIW...
(I am happily single now, and don't regret leaving.)