Well, not sleeping next to a drunk is a solid boundary and one that I also have (RAH isn't allowed in the house when he's been drinking, my biggest qualm is the drunk alcoholic smell. Barf.)
My suggestion for keeping him out of your bed after he's been drinking would be passive aggressive, rather than direct (taking his pillow off the bed and leaving it on the couch, putting something uncomfortable on his side of the bed like shoes - pointy shoes, etc.) but in my experience these practices were guarantees at starting fights with a drunk. No thank you.
Honestly, I would communicate that if he's been drinking you would appreciate it if he sleeps on the couch because he's a very active drunk sleeper. If you communicate that and he persists on sleeping in your bed anyway then I'd say it's time for YOU to do something different (boundaries are for us, not rules for them). In my case, we separated. No more drunkies in my bed.
And no more drunk alcoholic smell in my house.