I've used composting toilets many times in the past. In fact, my brother's house has one. Composting toilets use no water, so you don't have to flush. How does it work? Since your waste is mostly made up of water, a composting toilet helps evaporate that water, and what's left gets broken down into soil.
In case you were wondering (I know I was), a correctly installed and operating composting toilet shouldn't smell at all. Check out this video to learn more about them.
You can purchase composting toilets for your home or cabin. Want to see what they look like? Then
Check out these made by Sun-Mar. Some are self-contained, meaning they just contain the seat and an opening to a drum below that holds your waste. Others called central units, have seats in the bathroom, and shoots that go down to a separate holding tank.
Here's another video by a happy composting toilet user. This self-contained composting toilet holds all the waste, evaporates the water, so you're left with soil your lawn and flowers will love.