The toilet flush is one of the oldest stock sound effects in comedy, long used in radio, cartoons and pranks to suggest a bathroom without showing one. Online it took on a second meaning as a rating in audio form, a way to say an opinion, outfit, song or attempt belongs in the toilet. Its near six second length gives editors both the dramatic drain and the refill tail, making it flexible for short meme cuts, soundboard spam in chats and longer awkward pauses in reaction videos.