I have no problem telling them to turn it off and the same goes for the DP whose pipe comes out the drivers side. One guy was gassing us out and said he didn't realize about it. Told him to buy the long pipe and pipe it up over his roof.
Most of the time people just don't think and a gentle reminder is enough. Then again you get non rver's who once a year go out and terrorize the rest of us. Ranger rick is definitely an option I the am so they can be spoken to more firmly by someone other than you. As for the one suggestion, we generally avoid the weekends as much as possible and completely avoid the holiday seasons.