Actually - I do wonder why we pump out human sewer out to sea instead of inland ... dry it in big piles and would make a fabulous fertilizer ... we use animal waste, which is very nutrient rich, so why not human?
Pee in your hotwaterbottle - solves two problems at once
Keep a bucket in the laundry and keep topping it up - after about 3 days it's great for bleaching whites (according to the ancient romans)
