I've used DE for over 20 years to prevent mites, lice, ants, etc., successfully, and this is for two macaw parrots as well as a flock of silkies, and keeping ants out of our house.with any wild animal there is a risk of parasites. if shooting a raccoon is what you need to do to protect your chickens I think most chicken keepers wouldn't really consider that waste.
maybe do a round of diatomaceous earth if you decide to feed it to them
But, if the chickens had worms, I'd get Safeguard for them.