It depends on what kind of hats you are talking about, how often you wear them, where you wear them, and how often you wash your hair.
If you mean ball caps, throw them in the washing machine and dryer. Do it when they get dirty. If you mean pull on knitted caps, hand wash them or wash them on gentle in the washing machine and lay them flat on a towel to dry. Do it when they get dirty. If you mean a for real hat like a fedora or cowboy hat, use a lint brush when needed. You don't wash for real hats like that.
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I'm giving it another shot. We will see.
My forum is still there and everyone is welcome to come join as well. There is a private women only subforum there if anyone is interested. Also, there is no CAPTCHA.

The link to the forum is
http://www.rightplanet.proboards.com