"Rude Removal" was a short set to air on "Dexter's Laboratory" that was promptly pulled by Cartoon Network due to its content. It was produced in 1997, and there are reports of people who had seen the short (uncensored) at conventions back in 1998.
The episode involved Dexter inventing a device to remove the rudeness from people, but it backfires when it splits Dexter and Dee-Dee into both rude and nice versions of themselves. They swear in the short, and although it was censored for TV, Cartoon Network believed it was still too inappropriate.