We have an old-timey outhouse on our property. For the past fifty years, our family has only spend a month a year there (two weeks in spring, two weeks in fall). So the outhouse has had time to recover between visits, and only has started to be pretty foul toward the end of each visit (or we've added lime). But now we're starting to spend more time there, and I'd like to upgrade the existing structure, but I'm not sure what's best.
In this photo, the current outhouse is the one in the distance (visible under the treehouse). The one up front has long-since been removed, but it's identical to the existing one. There is not much by way of a pit below ... you hit rock fairly quickly. I was thinking that if we built in a back door and maybe inserted a bin that could be rotated out? And start using sawdust instead of lime?