I'm taking over the teen board today, it would seem...
This is a bit grim, but I have asked DD (12) now she's started her periods, to put any stained pants into a bowl of hot water and vanish by the washing machine.
Seems she can't be bothered and either "forgets" or just slings them in a bowl of water for me to sort out.
I don't really see why I should. Am I being harsh?