A crude humor tool

slapstick / slæp-stik/ noun

1. Two flat paddles used by Vaudeville comedians, one hinged to the other so that when something (or someone) is hit with it, one slaps against the other delivering a much louder bang than expected. 

2. [Noun, mass] The kind of crude humor based on knockabout melodrama and farce, with or without slapsticks.

Dr. Goodword:

Slapstick came to us be way of synecdoche. Synecdoche [si-nek-dê-kee] is a type of metaphor in which a part of something represents the whole. If your pal asks if you have wheels, meaning a car, he is guilty of synecdoche—a poet who doesn't know it! A slapstick was once a prop so tightly identified with broad humor that it became our word for that type of humor itself.

 Wikipedia enslightens:

The phrase comes from the battacchio—called the 'slap stick' in English—a club-like object composed of two wooden slats used in Commedia dell'arte. When struck, the battacchio produces a loud smacking noise, though little force is transferred from the object to the person being struck. Actors may thus hit one another repeatedly with great audible effect while causing very little actual physical damage. Along with the inflatable bladder (of which the whoopee cushion is a modern variant), it was among the earliest forms of special effects that could be carried on one's person.