Well, to be fair, the vagina is connected to the uterus via the cervix. I'd imagine she could possibly get alcohol into her bloodstream once it reaches the uterine lining (endometrium), which has quite a large number of arteries supplying blood to it...
...No, I'm no doctor. Wikipedia is more than enough.
All mucous membranes allow alcohol to pass through into the bloodstream. So it would work. And also be uncomfortable and dangerous if you're not an oni.
Aahh, maybe it'll taste better with this mouth...❤Ah, but this makes me a little dizzy...