If rinse constantly with listerine, how much of the alcohol from that will be absrobed into the bloodstream?
Effectively none. You’ll probably absorb more as vapour through your lungs than you will through the membranes in the mouth. Alcohol dries the membranes and prompts the secretion of mucous which protects them by preventing absorption.
So…it dries out the mucus, and then the membranes secrete more mucus? Sounds like the membranes will be fine.
Speaking of which, your stomach and the rest of your GI tract is one big mucous membrane. And it absorbs alcohol just fine. Rinsing your mouth out with Listerine won’t do much because you’re missing two things:
- surface area, and
- residence time.
If you drink the listerine, it sits uninterrupted in your stomach and small intestine. Lots of residence time, and much more surface area than your mouth.
Also, the surfaces in your mouth can absorb things - note the sublingual application of nitroglycerin to treat acute angina - but it’s not as optimized for the job as the rest of your GI tract is. Your stomach and small intestine are really good at it (that’s their job!), but so is your colon (large intestine). Several years ago a man died of alcohol poisoning after his wife gave him an enema composed of sherry. He was an alcoholic who couldn’t drink because of a throat problem, and his thoughtful, loving wife thought the best way to help him was to cram a bunch of wine up his ass.
What if you, say, rinse for 5 minutes and repeat?
It is possible to absorb ethyl alcohol through the mouth, however in most cases it won’t be a significant about. There is an exception though, if you are on a medication that impairs the metabolism of the alcohol, you could have adverse effects from normal mouthwash use.
So, if you are on a medication that produces “disulfram-like” effects, avoid alcoholic mouthwash.