Some sort of gizmo? Other than turning the entire water supply off. We've already had a flooded bathroom and kitchen this week, I have had to turn the kitchen tap off 3 times in half an hour this morning and with half term next week I am going to get sick of it (ds1 turns the taps on full blast and then stims over the water flow- turns his head to one side and flicks his eyes backwards and forwards- so he's very keen to do it).
Help!