Once, I took my yellowed white dress made of a fine white liberty-lawn-type cotton out. I was so disgusted with the yellowing that had occurred. I washed it, the yellow did not come out. I hung it out to dry, and I left it out on the line for several days. The sunlight got rid of the yellow, and I was very happy. You might want to try that. We often forget the bleaching effects of sunlight.