The concept of "banned words" (other than the offensive stuff, of course) in a classroom is so funny to me. There is no way that the person who came up with that wasn't the sourest loser ever.
I remember that the vice principal of our Christian high school was annoyed with us saying 'gosh darn', and made the mistake of telling us, "If you're going to say 'gosh darn', you might as well say 'god damn', because that's what you really mean, and the Lort knows your heart."
... We all just started flat-out saying 'god damn' like we were told.
I'm a school bus driver and we're supposed to not allow foul language. It's only a problem on the middle school runs, and it's not really worth the effort on my part to do anything about it. I'm just happy when I can unload all the kids and nothing has been set on fire.
I taught math for a couple of years in my local rural school. The fastest way to get kids to stop using certain annoying words or phrases was to start using them myself. It absolutely ruined the vibe they were going for. Particularity if you used them wrong.
Still, it seems kids need that type of 'creative' outlet.