DE and Sulfur will definitely get rid of chiggers, ticks, and just about every other insect on the property.
Just mix the two and spread in a fertilizer spreader.
The alternative is 7 dust which I can't use because we're close to a pond and I don't want the run off to get in the pond and kill the fish.
Even if it doesn't kill the fish, I don't want to eat 7 dust later on.