I use BOTH DE and sweet PDZ.
Sweet PDZ (or Stall Dry) are horse-stall products that -I believe- absorb and neutralize ammonia to cut down on smell. They have no anti-parasite properties like DE.
DE can be used in bedding, feed, and to actually dust chickens with. My understanding is it's tiny...
ASk your feed store if they can special-prder it. It must be (chemical codex) food grade DE. No one local carries it but they special-ordered it for me. Much cheaper than shipping from online orders.