I don't care for DE. But I bring a dish of good ol' dirt from the back yard in to brooder chicks. They love it & they get a little exposure to whatever might be there.
Any standard topsoil will do the trick! I would let my chickens free range in the backyard and they would find a spot in the garden to park themselves and bathe. You can mix in DE which is good for getting out mites and other parasites, but I never personally used it. I looked into it, but went with the old fashioned dirt. Chickens are pretty good at taking care of themselves, so they'll find a spot they like in the run and bathe.