If there is writing on it in a different color than white, then it's a little harder, if not just hand wash it in a bleach solution, if it has writing on a color other than white, then you could throw it in the washer after putting it in a bag for lingerie. I've tried the frame that you use in the Dishwasher, and I really don't like that It made my hat a little funky. Another possible solution is to wash the hat by hand with dishsoap- it works really well on many forms of grease including the natural greases and oils in hair.
There's a device you can buy (a frame) so you can put the hat in the dishwasher. The frame will keep the hats shape...Why do black people stare at white people?
put it in the washer and put cloroxWhat does it mean when a guy tips his hat?
I Just took some bleach on a white towel and scrubbed it a little bit, no big deal, it didn't fully take the dirt out, but, it did really help a lot, so thats my suggestion!
hope it helps! -angie.