This weekend I was in the mountains quilting with my round robin buddies and making the ribbons for our Sept. quilt show. I accidentally scorched my quilt blocks while pressing them and tried several things to remove the scorch marks. Then I remembered an old tip to whiten nylon under clothes: soak them in dishwasher detergent mixed with some water. I poured out a small amount of the gel detergent and rubbed it on the scorched places with a scrubby sponge. It started immediately to remove the brown scorch marks from the cream-on-cream fabrics in my project that I want to put in our show. The gel detergent has bleach in the formula! There is one small spot where the bleach lightened a dark red fabric adjacent to the cream fabrics, but it is hardly noticeable.
After rinsing the area really well, blotting it dry with a clean towel, and letting it air dry a while, I was able to press (on a lower heat) the area. No one will ever know what happened.