My best HS teacher got into hot water one year over a similar lesson plan. He was on the topic when all the students got vehement they couldn't be nazis, because they were good people who wouldn't do it. So he said, okay, it's extra assignment time: design a concentration camp. The secret was you get an A for saying no and an F for anything else.

Got the local news in a tizzy. But taught 30 little sheep they could be lead anywhere if they didn't use their heads.