{GOF Quote -'Myrtle ... what lives in the lake, apart from the giant squid?' 'Oh, all sorts,' she said. 'I sometimes go down there ... sometimes don't have any choice, if someone flushes my toilet when I'm not expecting it...' Trying not to think about Moaning Myrtle zooming down a pipe to the lake with the contents of a toilet, - GOF Quote}
Harry decided that nothing was important enough to warrant swimming in the schools septic tank, in-front of everyone. The Boy-Who-Lived-To-Swim-In-Sewage. No thanks.
After the merpeople returned Ron to the shore, he was livid at not being rescued. He and his fellow hostages were more upset to find that they had been chucked in a toilet. Fleur and Cedric were ecstatic that they had used a spell that kept the filth from their mouths, and Victor Krum was violently ill. He also had a nasty case of tetanus.