I've heard good things about the "Restoration" product from some of our guild members. They like the product and have had success in brightening vintage quilts. One member restores quilts and she highly recommends it as it is supposed to be gentle on the fabric however she soaks the quilts in her bathtub and does not use a washing machine for the process.
I agree with Quiltingshorttimer and would not use the Ritz product.