Yep...that's one of the great advantages to DL in the coop and run...what comes up from the earth to consume the feces. They keep the soil loose for good water absorption, they digest the fecal matter and they provide extra food for the flock. One article I read said that a flock on DL could provide a good percentage of their protein needs.
Our run is pretty big, so it would take a lot of shavings to fill the whole thing. But there are some spots where I think it would be great to put a thick layer of the shavings ...
One of the things we do on this farm is "heel in" nursery stock that's been dug and bundled but not shipped. We use shavings for that. So maybe we can steal some shavings from those spots now that the season has passed. I bet those shavings would be well started with life.