I'll be looking into using biochar for my friend's chicken coop. He runs a woodstove for heat in the winter, so there's a source of charcoal. You do have to separate it from the ash then pulverize it. It's supposed to make a really good bedding that absorbs all odor, digests the wastes via microbiome, and when you clean it out of your coop it becomes the best fertilizer for your garden. There's lots of how-to's online. I'll be studying.
I'm hoping to get some fertilizer for my garden if I can convince him to do this, and make the coop more maintenance-free.