I have a couple of questions for the OP.
How do you usually teach etiquette at your dojo?
Do you have any written document regarding what's expected in terms of etiquette?
Yes we have a PDF of etiquette emailed and printed out, every new student receives this hand book. also a senior student discusses basic etiquette with new students before the start of their first class. This guy is basically the turd in the punch bowl; everyone else seems to understand the policies and put forth no opposition.