Chickens clean themselves by rolling around in dry dirt. Typically they will loosen dirt and dig a small hole big enough for them to sit in. They will sit or roll in the loose dirt. The downside is that the chicken area develops dozens of small indentations that I usually trip on.
So the dusting box is supposed to give them an easy place to "dust" and should prevent all the holes in the yard.
Nice idea if it would work.
My chicken book gave instructions on how to build a simple box, all of which was too much for me, but seemingly an easier thing for the brothers to do. I showed them the pictures in the book and gave them the dimensions.
The boxes turned out exactly like the one in the book. But also a lot bigger, heavier and more substantial than I had expected. I guess I was thinking they'd be more like heavy cardboard boxes. They were too heavy for me to move, so the brothers helped get them situated where I wanted them.
I decided to put one inside the coop and one outside. They made a lid for the outside one to keep the dirt inside dry when it rains. The one inside was a tight squeeze, so they removed one of the broken nesting boxes and modified the roost supports for it to fit in the corner. I should have measured better before having them built.
The goal was to fill the box about 5-6" full to give the chickens plenty of dusting material. So I filled the boxes with two rounds of:
6 parts peat moss
1 part diatamaceous earth
1 part wood ash (I'd been saving from our fireplace)
The book also suggested to sift the material, but I didn't have a suitable sifter (which may be my next project for the brothers) so just picked out the bigger pieces with my hand.
I'm hoping the chickens will eventually use them. So far they perch on the edge of the outside one. And lay eggs in the inside one.