I was given some upholstery fabric several years ago. There was a label that said it was cotton, but needed to be dry cleaned. I just tossed it all in the wash. One piece did not survive but the rest came out great. It was thicker than qulting cotton, and I used it for a back on a utility quilt with no problem. Don't see why you couldn't piece with it.
I think dry cleaning was recommended to preserve the finish.