I have used the Willow feeders at the lab. It’s hard to get over the outhouse feel of it. And the ones with the multiple holes so you can share with a friend. I didn’t like that in the army and I still don’t like it. I guess the worst part was when you finish your business and you have to cover it. The flush and forget, at least for me, seems better than having to look at yours and everybody else’s and cover it. I did like that. It wasn’t a “see how they run” situation where you count how many mice come in before you get it covered up. And the urine separator toilet seat seems to be a tricky part to build and plumb, but necessary as those two bodily functions can be tied together for a lot of people.
I would like to see a good design and hopefully manufacture of the pee separating toilet seat. Tim Barker and I kicked around adding a separate bucket filled with activated charcoal for the toilet seat pee and the urinal. Once that was all soaked in, we were going to use on garden or maybe sell bags of it at the Missoula farmers market as organic garden additive.