Interesting in Japanese schools, many Korean schools etc that pupils generally clean schools for up to half an hour at the end of each day, including the bogs. They learn to take responsibility for all litter, mess, rubbish and so on, regardless that they may not personally have caused it. It's a long term strategy, but now would be a perfect time with a perfect excuse to introduce this cultural change in the UK starting in our schools. Too many people leave rubbish in the countryside, around town etc and don't get the connect between leaving a mess and someone else clearing it up. Give 'em all a bog brush!