Bus trip to their nearest city, downtown, drop them off and let them figure out a way to get back home.
Increases their problem-solving skills and shows who can manage on their own and who needs to call mommy and daddy to be picked up.
:shrug:
Same thing in every class. 20% would pass and help the rest. 60% would find a way...eventually. 20% would be buying crack as soon as they entered the city.