I would consider it rude to do it in the first place (detailed personal grooming* in public places is a big no-no!), but to refuse to stop when politely requested is really rude. I would think that people should be more considerate than to intentionally and knowingly continue doing things that stink the cabin out.


*Anything beyond a quick touch up of one's nose and lipstick, which I would not do in public but generally accepted