Both my hens and I are afraid of mites from now on! Our darling EE girl asked me to take out the newspaper and shavings, and she layed a lovely egg on the clean bare floor of her plastic (and dusted) tupperware. First, she dug to china on the bare plastic floor anyways, then her roosterly friend settled her down and they happily layed an egg together.
Maybe once they're used to the whole egglaying process, the nesting material may not be as important. Our girl will be three years old around christmas, she's been doing this a long time.
Of course, carpet squares would be easy to wash, dry and put back in. But the mites of this summer were SCARY bad. Ooooh. Bad. They were scared of the coop for a few days. Now she takes a good long look into her new nest box and sort of asks us to check it for her. She likes to see us wipe it and dust it.
So I'd be real careful with carpet squares if mites could get in..........