flush the tubes

To perform an action that improves the speed of your internet connection.

Normally this refers to removing something that was previously slowing your connection down.

Guy1: The internet connection is running really slow. we need to flush the tubes.
Guy2: I'll just go reset the router.

Guy1: Did you hear about the power cut earlier?
Guy2: Yeah the internet is running way fast, everyone on the streets torrent downloading must have been stopped when the power cut.
Guy1: I guess the power cut flushed the tubes.