I would wash after quilting. I have yet to have a stain that the following would not take out: A paste using blue Dawn, Baking Soda and Peroxide. Spray spot(s) with a little water; place blue Dawn on spots, sprinkle with Baking Soda and then spray with peroxide. Rub in with a toothbrush. Leave set for at least an hour or even longer. Repeat after each wash as needed, maybe allowing more set time.