My brothers attended an all male Catholic high school. There were Saturday detentions for things like fighting, chewing gum, talking back... The Brothers had their Saturday work force and weeds were pulled, mulch put down, walls painted, windows washed, bulbs planted.... whatever needed to be done. Believe me, you learned a lesson about smarting off to a teacher if your Saturday was spent painting a wall.
Sounds like a good idea for any school, not just Catholic.