I agree. I do some online gaming, and by far the most enjoyable group was the one where any profanity or inference of profanity was thrown out with one warning. Even the slightest infraction got people bounced after the first warning. Those who wanted to stay learned, and as a result, people had fun. There was very little disrespect and trash talking, and people policed themselves. There didn't even need to be a moderator, as soon as someone said anything remotely bad, other players would gently warn.
This method works with raising kids, too, I understand.