With the above ground kennels I would just hose it out the back and put lime over it from time to time. It hardly ever smelled.
With the concrete slab I was going to install a septic, but decided not too due to cost. I may do it eventually. So I scoop it up and put it in a designated bucket with a garbage bag and lid and put it in trash once a week. I also still spray out with hose when I dont feel like scooping. And when I mow the lawn I just put mower on lowest setting when I mow behind kennels.
I feed sportsmix 24/20 and I have been giving all the dogs probiotics (thanks Thomas). With this they only make one stool a day and its hard which makes easy to clean. I also let all the dogs run everyday and for the most part they will just empty out then instead of in the kennels which means I hardly have any cleanup.
Can you pm me on the probotics. You give