"Psssst....waitress. I will pay their tab, and throw in a 30% tip, if you throw them out."
Christmas Eve, 1999 (or was it 2000) that was pretty much what we did in a bar in Dover. Folks refused to go sit in the non-smoking bar (which was empty) but insisted we (nearly 30 of us) put out our cigarettes. It was a non-smoker at one of our tables that told the waitress she would pay their tab when thy refused because the waitress refused to tell us to stop smoking. I think her tip from us was around $200 that night.......and we were all home by 8pm.
"Psssst....waitress. I will pay their tab, and throw in a 30% tip, if you throw them out."
Here's a good cartoon: