When I was in highschool, to stop kids from getting into trouble so much we had 3 hour detentions. We had to go to a room, put our hands flat on the desk and stare forward for 3 hours. at 1.5 hours we got a 5 minute break... I usually left at the 5 minute break if I wasn't fucked up.

Then after serving enough of those I just said fuck it and told them to give me OSS everytime instead of the detentions...