I remembered how John Flynn finished his rag quilts.
After all the seams have been clipped, it is time to whack. You can tack the quilt down to a sheet of plywood or tape it to a clean concrete surface. Unless you have a big open work area like we do, you’ll want to do this outside.
Use an electric “Weed Eater”, not the more powerful gasoline model. Just angle the head of the tool so the plastic cord whips the quilt’s edges to fray them. You can see how well you are doing as you go. Keep after the edges until they are all fluffy.
Wash the finished quilt and dry in the dryer.