How can I effectively bleach a cotton polyester blend fabric?

To effectively bleach a cotton polyester blend fabric, mix a solution of bleach and water in a ratio of 1:4. Soak the fabric in the solution for about 10-15 minutes, then rinse thoroughly with cold water. Repeat the process if necessary, but be cautious not to over-bleach as it can weaken the fabric. Finally, wash the fabric with a mild detergent to remove any remaining bleach.