If you can find a product called Amaze, it is made by the folks who make Sunlight. It is really good. I wash my antique christening gowns in it and they come out snow white. Someone also mentioned using Oxyclean. It is really good as well. Fill your bathtub with slightly warm water and soak the quilts in the Amaze or Oxyclean over night. Rinse the water, gently squeeze out the excess water and fill the tub again using the cleaning product you have chosen. You may have to do this a few times.