Oh how we all have suffered at one time or another. Go ahead and try all these remedies.....they all work on some dye bleeds, but the manufacturers keep getting ahead of us with their new dyeing methods. After you have done your best, go ahead and proudly display it and make no apologies. No quilt that you made with love deserves to be put in a closet.
And if I was considering buying the quilt personally, I would be glad to know the extent of any red dye bleed. I would pass on any quilt with red because I would assume it had not been washed and I would worry about the "unknown bleed". I would pay a little less, but at least I would buy it.
I once made a red and white Jacobs ladder king size bleeder and, worse, the blue marker bleed into the batting and backing (documented in my QB Blog). After trying all the products, and weeks of scrubbing and drying, most, but not all came out. I was so discouraged but my daughter came along, saw it, scarfted it up, and it has been on her bed ever since .... about 2 years now. And when I visit her, the quilt is so lovely, I do not notice any of the remaining marks....and she still loves it. So cheer up, chin up, no quilt is perfect, but we love them all!