Sweet PDZ is a stall freshener. It is a granular substance and works great to sift out chicken poop.
Sweet PDZ Stall Freshner
Horse stall refresher is made of an all-natural, non-toxic and non-hazardous granular mineral. Contains no masking scents or perfumes. Absorbs moisture and neutralizes ammonia and odors through cation exchange (a unique neutralizing process associated with Clinoptilolite Zeolite, Sweet PDZ's main ingredient). Safe and superior alternative to hydrated lime and barn lime. Extends bedding life, reduces fly population, environmentally "green".
Here is a pix
There are many different brands also. You can get at most feed stores as well as places like TSC.