Cleaning a hat that is flexfit and cotton polyester blend?

Question:How do i clean the hats? I have two white ones that were pristine when I bought them, but now have a dingy white appearance to them, and I would like them to look that way again.. any suggestions?

Answers:
get a hat washer. It's a plastic clamshell, they sell them at walmart, or lidz.com. You can put it in the wash machine(no drying), or the dishwasher.