Swirly
On television, one or more bigger people, usually high school boys, pick up the victim.  Then they dunk the victim's head in a toilet and flush it.  The swirling water gives the swirly its name.  For example, on the television show Archer, Archer tells Lana about how he got pneumonia from getting a swirly in high school: Two bigger boys had picked him up, turned him upside down, and put his head in a toilet.  On The Simpsons, Bart Simpson gets a swirly from Jimbo Jones. In Cobra Kai, Kenny gets revenge against Anthony LaRusso by dunking his head into a used toilet.