It seems to me one can keep things clean without using modern technology. It would be more work, but the Amish aren’t afraid of work.
The solution here is simple, don’t call them outhouses. Call them composting toilets. Swear that you owe allegiance to the great AlGore and are fighting to save the planet.
I’m sorry, but dumping raw sewage onto agricultural fields doesn’t seem the least bit “clean.” I agree with trying to avoid a lot of modern technology, but I have to draw the line at raw sewage.