When SECMOL, a Ladakhi-run organization in Ladakh, Indian Himalayas, buiult its solar-heated and solar-powered adobe campus for 40 to 150 people, of course we didn't want to use flush toilets.
The traditional toilet arrangement in the area uses a hole in the floor over a room, the manure chamber, and layered with dry garden soil or ashes or cowshed bedding. Because the chamber is pretty big annd the climate is bone dry, there is more drying than composting. It is an essential part of local farming, though.
Using compost knowledge, common sense, and inspiration from the Humanure Handbook, we made a couple of changes to the tradition, and have been using the toilets for four years now, and are very happy with them. We don't have to trannsport buckets because the bathroom is right over the pile.
The access to the user's bathroom can be attached to the second floor of the house so it doesn't have to be an outhouse, though ours is. Below the bathroom are two manure chambers, as wide as their doors (about 2.5 feet, in our case), and about six feet long. So the bathroom above is about 6x6 feet in size, with four holes in the floor. At any given time, the two holes over one manure chamber are open, and the two holes over the other chamber are closed for the year. We have a moveable wooden box with a seat over one of the holes and a simple hole in the floor for the other, since most local people don't like a seat.
In mid-winter we empty the chamber that has been closed off for a year, and then open the holes over it and close the holes overe the one that has been being used. Then in spring we cart it off to the fields and gardens.
All the paper, newspaper, office paper, and even tatmpons and the cotton part of sanintary napkins are decomposed without a recognizable trace. But the sawdust and wood shavings we used the first couple of years (unaged, unn-damp) were undecomposed. For the past couple of years we've been putting the sawdust and shavings in the cowshed first as bedding, and then shoveling it out periodically for the toilets. I hope that will decompose more fully.
We have four of these toilets with double manure chambers, (we have no shortage of space) serving from 40 (all the time) to 150 (for a few weeks at a time) people and it is plenty.
We buy a truckload of sawdust from local mill and workshops, use what our own carpenter produces, and also put our autumn leaves in. the traditional cover is dry soil and we put that in too when we run out of cowshed diggings for a few weeks.
(All kitchen waste and weeds are fed to the cows, by the way)
If we were in a wetter climate we'd probably want to put some perforated pipes in the chambers for aeration. If we could not afford to buy sawdust Ii guess we'd just use what we produce and leaves and dry soil.
I hope others find this useful! Unfortunately the local govt is talking about installing a sewer system in the town, but we won't have to join it.