I had better luck just getting broody varieties, as opposed to trying to convince them to set. Our broodiest full size birds were always Buff Orpingtons, but we had a Barred Rock or two that did the job as well. Otherwise, get a couple of banties. You can put full size eggs under them and they'll gladly raise those, too. I don't think any of our Auracanas ever set on eggs, but they sure were pretty birds and we liked the colored eggs.
You can try taking a next box, letting a few eggs get piled up for a day or two and then putting one of your barred rocks on it and closing her in somehow for a couple of days. We did get that to work once or twice early on in our chicken raising days, but the banties were just so good at it naturally we just let it go after we got some of them.