I have removed several tough stains from various pieces of clothing by using OxiClean granules. It has never discolored or damaged any of the fabrics. I wet the stain, cover it with the granules, add a little more water, and rub the granules/water area with my finger. I have rolled up the piece of clothing so the granules/water don't dry out. I usually leave it for a day and then check it. Usually the stain is gone; on a few occasions, I added more granules and water, rolled it up and left it another day. Rather than roll up the quilt, you could just put a wet crumpled cloth on top to keep it moist. The only thing I have been unable to remove is soy and teriyaki sauce. Recently I looked online how to remove soy sauce and it mentioned vinegar and it also suggested peroxide, so maybe you can find info online if the OxiClean doesn't work. Good Luck