"They don't bloody well belong on 121.5."
Er, Yes they do! Practice Pans and Training fixes are prefectly legitimate uses.
Unless they are blocking more urgent airline pilot chit-chat about toilet emptying requests and rationing for the next sector, etc, of course.
And yes, our company policy IS to listen out on 121.5. Our radio has a volume control though. Turn it left if required, legitimate use (or airline mistakes) get quieter, turn it right when it's all complete, no problem.