Well, I'm sure there will be some of you not happy with this, but I use DE by lightly dusting about 1 cup over a 32 s.f. area and working it in while the chickens are
outside playing. I've only done this twice in about 3 months - mainly because I had to remove and replace a bunch of pine shavings cuz of the insane rain we've had this spring. I also make a concoction of peat moss, wood ashes and tiny bit of DE for their dust bath area.
Think of the deep litter method as a compost pile, slowly breaking down the poo, that you have to regenerate as needed by adding another inch or so of shavings. My chickens do a bunch of digging in their coop, so I rarely have to stir it up like I use to! My coop isn't set up with a droppings board and I have no smell at all, but will probably add one in the future, cuz it can't hurt! All of the openings into my coop are covered not only with 1/2" hardware cloth, but window screen as well to keep flying critters to a minimum.
Please read this!!!
http://www.dirtdoctor.com/organic/garden/view_question/id/265/
Sorry, but there is evidence to support the use of DE and it's
my personal choice, but only sparingly. My vet just told me he worms his chickens with a poultry wormer twice a year to prevent worms getting in the eggs themselves! Yeach! He said it's pretty awful to crack an egg and see a worm inside... Not sure if I will do that, but will probably do so at least 2 weeks before they hopefully start laying and again when they're molting to prevent any residual medicine getting in the eggs as well. He said no matter what precautions you take in your yard or run, outside birds, animals, etc. can bring those problems in.