Shampoos are for the head, genius. And I suppose it’s just a big-city thing . . . I suppose out in the land-of-folks-with-no-teeth people like you expect to get away with such antics.
Oh, sorry. So instead of anal rape, you think he should have his skull crushed by a police officer using a baton weapon on him while he's handcuffed on the ground, an act you find appropriately referenced by the fun word "shampoo."
My mistake. Wouldn't want to miss your nuance or anything.