Composting toilet. Inventor Buzz Burrows holding out an example of compost produced by the Rota-Loo, a dry toilet he has developed. Composting toilets use bacteria and heat to control the decomposition of human excrement. Such toilets do not require the large amounts of water in conventional flush toilets. The end product is an odourless humus material that can be used as a fertiliser. Using this process, humans can produce several kilograms of organic fertilizer every few months. Photographed in Melbourne, Australia.