During Prohibitionbootleg gin was called Mickey Finn - just a form of rhyming slang (I do believe). Basically, it was gutrot.
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Batshitmentalist is sane for once,
Tue 4 Nov 2003, 8:54,
archived)
It means to slip a drug into a drinkI'd always heard that it was named after a bar owner who slipped some knockout chemical ( I don't recall what) into drinks, and take the passed out person in the back, rob him, and put him in the alley in rags instead of clothes. The chemical also affected their thinking when they woke up. MAybe I should check snopes.com . . .
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Thu 6 Nov 2003, 1:51,
archived)