>>101091572It's simpler than you think, OP. It's just a bucket with a seat above it. When Rolf is done, he takes the bucket out, cleans it with the hose, and puts it back in. That way, he can use his own shit as fertilizer (saving money and resources if Beatrice isn't shitting enough) and doesn't have to worry about plumbing.
If you're asking "well what's the point of the outhouse then," it's a modesty thing. Rolf is from the old country, but they still have standards.
