Today’s society isn’t concerned with using their parts for the activities for which they were designed; they’re interested in participating in activities that provide thrills.
They aren’t designed to absorb alcohol, but they certainly can. These are very permeable tissues that can transfer drugs directly to the bloodstream. That’s why drugs in anal suppositories work so quickly, and why anal sex is such an effective way to transmit AIDS.
Oh, I imagine it would work all right. Probably a very fast route to intoxication. I would think it would burn like crazy.
Ethyl alcohol can be absorbed through mucous membranes. It enters your bloodstream to a small degree through the mucous membranes in your mouth even before you swallow. Perhaps the same mechanism is at work here.
Your hand is covered with tough and non-absorbing skin. Vaginas are lines with a mucosal membrane - think lining of your mouth.