Hi. I have a problem and if anyone can come up with something - it's you lot 
My youngest (11) is swearing. He will just suddenly exclaim "shit" "crap" or suchlike. Now he has added "dickhead" and "fuckers" to it. I am mortified. This is NOT language we use at home, I promise! The internet is restricted (net nanny) youtube is blocked. tv is controlled.
He is saying it at school.
Things that don't work (cos we've tried and tried)
telling him off
taking toys away
taking internet turn away
taking tv turn away
social story
cartoon story (where you do a cartoon grid and use speech and thought bubbles)
telling him we're sad
telling him it's wrong
sending him to his bedroom
star reward system for not swearing
removing him from the situation
It's not that he doesn't care about the above as such. It's that it doesn't stop him.
"shit"
"We don't use those words."
"sorry. shit"
No matter what you do - and no matter how upset he is, because he can get really upset about it - he still says them.
And he says that he's a loser and he's started punching himself in the stomach
.
I am at a total loss. All ideas most welcome.