One of my favorite classroom anecdotes about using (er...um...NOT using) bad language was when a student made a comment that I didn't understand, but the inhale of student breath nearly created a vacuum in the room. I asked a nearby student (I'll call him Jerry) what was said.
Jerry said, "Uh, you don't want to know."
I said, "Yes, I do."
Jerry said, "Well, he called her... well, he was talking about ..."
Jerry paused for many seconds. I think he was trying to think how to repeat the comment without "repeating" the comment. I waited patiently.
Jerry took a deep breath and said, "He was talking about her kittycat and he called her a garden implement."
That's a story I have been meaning to send in to Reader's Digest for years, but I've never gotten around to it.