Hi, welcome to BYC!
I think EVEN food grade DE is harmful, not only to my chickens but to myself, my family, and the environment. And the over rated and over used stuff isn't welcome at my house.
Curious... how do you KNOW it works well and not that you simply DON'T have the issue in the first place? Not all environments are created equal, nor are all chicken immune systems. Even among the same flock... some birds will have parasites while others don't.
Anyways, I don't mean to hammer you on your first post.

We are all here to learn from each other and our experiences.. even if it isn't the same as our experience. Thanks tons for sharing!