Things I did not know: apparently, there are alcohol suppositories. Supposedly popular among youths, partially because that delivery method bypasses the stomach, so you don't vomit.
I knew that alcohol could be absorbed by mucous membranes (from a medicine you were supposed to leave in your mouth for a bit for part of it to be absorbed there), but I wouldn't have thought to try those mucous membranes.
(The background was: after lunch, a colleague put his hands into this disinfectant/hand sanitiser machine, and then the corridor started smelling of alcohol. Another colleague mentioned that he was “old school” and preferred to take his alcohol internally. This triggered a small discussion of ways to administer alcohol.)