swirlie train
When a bully, or often a group of bullies, give a nerd successive swirlies (forcing his head into a toilet bowl and flushing) as a line of people - either the bullies themselves, or anyone who comes in and needs to go - come through to use a toilet. For example, if a group of high school jocks want to torture a nerd, they ferry him off to the boys' bathroom at the start of lunch period and give him a swirlie after each time someone uses the toilet until lunch is over, threatening to give the bathroom-goers swirlies of their own should they go against the bullies' orders to leave the toilet unflushed.
I just saw John getting a swirlie train from a bunch of the lacrosse bros. I went in the boys' bathroom and they were giving him wedgies and stuff; when they saw me come in they told me to do my business and not to flush or they'd give me a swirlie. As soon as I was done they carried John into the stall and dunked him face-first into my shit. I couldn't bear to watch but just hearing him scream as the toilet flushed was so sickening. I think they're still there, he's probably gotten at least 20 chunky swirlies by now cause all the sadistic jocks have heard about it and are going to that bathroom on purpose. Poor John.