Hi Mark, Unforunately the damage (yellowing) to your shirt is permanent. We never recommend soaking garmets for longer than 5 minutes. Sorry I don't have better news!

Hi Cindy, The best place for a definitive answer to whether or not polyester fibers can be safely washed with sodium hypochlorite bleaches like Clorox Regular-Bleach is any textile chemistry textbook. So yes, the fiber can be safely laundered with bleach. Typically, colored polyester fibers can also be bleached since the dye is applied to the liquid polyester polymer before it is extruded into fiber form. And polyester blended with cotton, regardless of the ratio of polyester to cotton, can also be bleached as long as the item is colorfast to bleach. What you have to watch out for is spandex, which can NOT be washed with sodium hypochlorite bleach. For those items, an overnight pre-soak with an oxygen bleach like Clorox2® Stain Fighter and Color Booster followed by a hot water wash (or at least the warmest water recommended on the care label) with detergent and more Clorox2 gives excellent whitening results. To determine if an item is colorfast to bleach, you can always use the bleachability test: add 2 teaspoons Clorox Regular-Bleach to ¼ cup water and apply a drop of this solution to a hidden part of the item (like a hem, inside seam or cuff). Wait 1 minute and then blot dry—no color change means the item can be safely bleached. Hope that helps! - Dr. Laundry