As the name suggests, these toilets do not require the use of water to operate. It is an ecological gesture that reduces the consumption of water while making fertilizer for ornamental crops.
The dry toilets are made up of a wooden frame and a flap, under which there is a stainless steel bucket containing carbonaceous material (like sawdust for example).
On the sketch below, the hatch to the right of the toilet gives access to a reserve of sawdust. After each pass, a ladle of sawdust must be added to the bucket so that the liquids are absorbed. Aerobic decomposition (in the presence of oxygen) will then occur, thus preventing the proliferation of odors.
When the bucket is full, it is emptied into a specific compost bin where it will finish its decomposition. So organic materials are valued for decorative crops and return to the garden in a virtuous circle!