On the subject of acceptability of faeces which was mentioned - herbivorous animals are OK but carnivorous animals tend to deposit faeces with nasty bugs in them which do not rot in the same benevolent way.
In this context all humans (including vegans) are classed as carnivorous as it is the intestinal configuration which is significant.
The US Forest Service instructions for people who hike in American forests says to bury your waste in the top few inches, the organic layer where it decomposes rapidly. A published book called "How to Shit in the Woods" recommends finding a place with a beautiful view but away from trails, paths, and waterways. Human waste will disappear in most woods in a few weeks depending on rain, etc.
I have noticed that cows tend to deposit their droppings on trails, and in these parts it can take 4 to 5 years to decompose. Must be the herbivore, course plant thing that takes long to decompose.
Bob