One of my friends carries a small stick of unopened deodorant in his bag. If he sits down at a table to play a game and someone is a bit ripe, he will offer it to the person quietly. All but once, the person gladly accepted it, as they were not aware they offended. The one guy refused the offer and we got up and left because he was really rank.
In general though, that has only happened twice at GenCon (the other times were at other gaming events) and I would echo the sentiment that gamers have done a pretty darn good job at overcoming that stereotype over the years.