Need help finding DE for fly control

[BamaBowdens]

I dust my coop, nest boxes and enclosed runs with de. I have allergies, have never had a problem with it. From my research, as soon as the DE touches moisture, whether water, mucus ect. It dissolves. I have probably eaten more of it than any of my 30 chickens. I did find a natural "soup" made with pumpkin seeds, garlic and a few other things. I will find it and post.no chemicals whatsoever for my birds. Excellent holistic wormer.

How does the DE keep the flies away? I'm trying the prometherin now and still see some flies, though not as many. Maybe I need to use the higher dilution ratio. I am keeping the coop and brooder pretty clean, and the surrounding surfaces. I think it is just the nature of the south in summer. We typically sit outside with our chicks and are trying to rid them completely without screening that section in.

Suggestions/advise?

Thanks!