Bleaching polyester requires the use of an oxygen-based bleach. Fill a wash basin or washing machine with cool water and an oxygen-based bleach. Follow the package directions of the bleach to find out the necessary ratio of water to bleach. Submerge the fabric in the water, and let it soak overnight. The next day, drain all of the water. If the item is not bleached enough, repeat the process.
Chlorine bleach should never be used for bleaching polyester, as it can ruin the fabric. Chlorine bleach removes the outer coating of color in polyester and can turn the fabric yellow or gray. Instead, use all-fabric bleach, which is safe to use on colors and whites.
For removing stains from polyester, first treat them in a solution of water and bleach. Then wash the stain in the hottest possible water, along with detergent and bleach. Stains on any fabric should never be treated with full-strength bleach. Once stains are treated with a diluted solution of bleach and water, they should be allowed to air dry. If treated stains are exposed to dryer heat, the stain may get sealed in by the heat. Older stains may take longer to remove and may require multiple bleaching treatments.