I'm currently working on my second crown royal quilt. I did not use stabilizer on the fabric from the bags. I would recommend washing the bags with color catchers before you even cut them apart. The purple bags (which was what I have used for the most part) is flannel. After washing and drying, I cut the bags apart, cutting off the top part of the bag that hold the cording for closing the bag. Then I cut the stitching off, cutting as close to the stitching as possible. Then cut the bags to get the largest cut you can get. Out of the small bags I got a 4" x 6" rectangle. I made the first quilt with only the fabric from the bags, front and back. I used black batting, and the binding was a purple cotton.
PM me if you have other questions.