Hi, kerphi and all users of phpfreechat
I'd like to suggest something like that...
If we have a bot in channells of chat called "Admin" or "Moderator" this will be discouragement for swearing people. Maybe this bot may talk from time to time, even 5 or 10 sentences just to make people participate in conversation.
You can have a closer look for detailed example on http://chat.tufat.com/stateless/
this is just an idea, i have no technical knowledge about its practicability for integration with phpfreechat.