When I was a river [rafting] guide we used toilets made of [military surplus wooden] rocket boxes.
The premise is to take a large Army rocket box (a toilet lid fits inside ) and use double lined plastic bags and plenty of powdered lime. Regular old lime for the disinfectant.
We would use on of these on extended wilderness rafting trips for 30 or 40 people.
Here’s how it works. Set up the rocket box and remove the large roll of heavy black plastic trash bags. Take TWO bags and double bag them and line the inside of the box.
Set the lid on top and ONLY put toilet paper and feces in the box. All urine goes on the ground. After doing your business take a small scoop of lime and sprinkle enough of the powder to cover the waste. After finishing, remove the seat and place the lid back on but don’t seal it. The next person comes along, takes the lid off (which keeps the flies out ) and puts the toilet seat on and does the same.
When a bag is full, remove it from the box, and tie off and then put it inside another bag in case of leaks.
This gets put in the trash bags for later disposal. ONE rocket box can handle about 30 people for a weekend easily going through 2 to 4 bags every 2 or 3 days. We always brought two, one for women and one for men. Once ready to break camp, we removed the bag of dump, put the bucket of lime, the roll of trash bags and the lid inside the box and sealed the lid.
This was VERY effective and met the U.S. Forest Service "pack it in, pack it out" rule.
Lime is a VERY good thing to stockpile. In addition to keeping the oders down on feces, it can also keep the odor down on rotting bodies, as will 20 Mule Team Borax. I use that for raw tanning hides and have some that have NEVER been chemical tanned and ONLY had Borax and are now going on 10 years with no hair slippage or odor. These are deer hides that I have made into rugs. - Mel