Recently, I have been in love with buying vintage hats of all colors, shapes, and styles. Since it is not possible to buy a new vintage hat, one must take precautions. I always tie mine in a bag and let them sit a few days to make sure there are no little mites hiding among the folds, ribbons, flowers, or seams. Then, spray with lysol, air out, and viola! Its time to wear your hat.,
If hat appears to be dirty, it can be wiped with a damp cloth and blown dry. If you have to go this route, be very careful to dry it well.
A few years ago, I was watching Martha Stewart and one of the manners in which she cleaned some vintage flowers was to put them into a bag of salt..shake it..a few times and then remove item and be sure to shake away all of the salt. You should see that the salt has absorbed most of the dirt.
Always try to store your vintage hat in a hat box or some type of container to keep it pristine and always smelling nice.