I used some composting toilets while camping in NE Washington a while back and was startled at how nice (or awful) they could be.
I use a 5-gallon bucket in a removable wooden frame I built (from found
wood, of
course!). (Like a shallow box on legs, with the top board sticking out beyond the sides (for handles), a hole cut into the top, with the seat attached.) Put that over the bucket, close the seat/lid.
Shredded junk mail and envelopes for filler material, plus
yard prunings, leaves.
I urinate into a funnel in an old vinegar jug (standing up--the handle makes it easy), then put that into compost or poured to plants, or onto the humanure bin sometimes. At night, however, I sit and urinate in the bucket. (I'm female, by the way.)
The
urine is what causes the odor, plus it makes the bucket very heavy, so I prefer to keep urine and feces separate as much as I can.
If I had to do it again, I'd build the frame bigger, to hold a urine "tank," plus add a diversion funnel/urine separation thingie. Also make it so I just open the lid, not lift off the entire thing, to access and empty the bucket. More like a closed box, with handles, and a wooden lid, to enclose the entire thing (hopefully to reduce roaches and bugs--I get some kind of flying little bug when it's too wet.)
I dump it into one of two compost bins (which I alternate every 6 mos) --that also makes black soldier fly larvae, which the
chickens love. I keep the bin covered until I dump the buckets, about once a week or so. That's enough to destroy the pathogenic microorganisms but not necessarily the material.
In the meantime, if the black soldier flies get to it, their larvae will grow big within 2 weeks, so if I find a spot with them, I call the
chickens over (they're usually waiting). And when there are no larvae...the chooks squawk at me!
(I haven't had much success maintaining a black soldier fly colony to
feed the
chickens, so this is a good compromise, even if it's sporadic.)
I sure do not miss the plumbing maintenance/bills!
Tips: Make sure to have at least one extra bucket and lid, in case you cannot dump the bucket because of health, travel, weather, etc. And watch for leaks, and have another vessel ready as a replacement at all times.
Also, have running water,
soap, brush, cover materials (I use shredded
newspaper or woodchips) for the compost bins themselves. The more fine, the less air space, and thus the less odor and volume. I also keep a dedicated fork there, to be used just for humanure.
This video helped me a lot:
https://www.youtube.com/watch?v=JuKyhUVbKwM
I use diluted Dr Bronner's liquid soap and water, with a brush, to scrub out the buckets (not just rinse, as he does).
After 6 months, I move the contents from the curing bin to hot compost piles, along with normal compostable materials, to be extra sure everything harmful has been destroyed. I let the bin I was filling sit for 6 months. And I begin filling the 2nd bin (which I just moved to hot composting), using this as my new main bin. I do this instead of 1 year curing, as recommended in The Humanure Handbook.
I'd say start with something. Don't get too complicated, and you can alter as you see what works for you...you know, like permaculture...start with something small, observe, and make changes!