In India they developed a kind of septic tank that they actively fed with every kind of organic material that they could. It produces gas that the villagers use for cooking. It's a win/win because it digests sewage and other stuff that would attract flies, etc., It provides cooking fuel without them having to cut down local trees for wood, or buy expensive propane or coal, and the end product is a very good fertilizer for their fields....with no surviving pathogens.
I suspect that it only works so simply because of the background heat of the place. I don't think it'd work without an awful lot of insulation in the North of Europe or the British Isles.
Good way to create soil for a rocky tropical island though