Whether stuck in a kettle for 10 hours, or occupying Hyde Park for the weekend, cramming (hopefully!) over 100,000 people into the streets and parks of London is going to require toilets. Remember, some people were stuck in Tahrir Square for 18 days! And managing our own shit will make it a more pleasant experience for us, as well as just being a good example of self-organised civilisation.
Basically, for those who can’t even be arsed (no pun intended!) to read that, you need a big (5 gallon?) bucket, and a load of organic material; rotted sawdust, peat moss, leaf mould, rice hulls, or grass clippings. Even shredded paper, although it’s not the best.
It would be really handy if we could find someone in London who could stockpile a garage full of buckets in the next month or so. Restaurants and fast-food places often get rid of dozens of them at a time, so it should be possible to scavenge hundreds before the big weekend.