Step one: feed everyone a laxative.
step two: have an equal number of toilets set up and when the time comes everyone will have to pick one toilet.
now for the good part some of the toilets will do nothing when flushed, the catch is some of the toilets will work in reverse meaning you get sprayed with your own s#!t. now if you wanted to be really mean only feed one person a laxative and make sure there toilet is rigged to fling the poo back at them.
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