The washing machine is one simple way to wash a golf hat. It is best to wash the hat on a short, cold water cycle, preferably in a non-agitating washing machine. Place the hat in a lingerie bag, which will prevent the hat from becoming snagged or disformed. Hat cases are also now available that allow you to place the hat inside of the case, then wash. This plastic device will hold the shape of the hat so it does not lose its form. Use a laundry detergent designed for delicate items to keep the hat looking its best. When the wash cycle is finished, remove the hat and let air dry.
Dishwashers are typically thought to wash dishes only. Ironically, the dishwasher is one of the easiest ways to wash most hats, including golf hats. Dishwashers use a more mild cleaning procedure, eliminating the agitation and spinning cycles of a washing machine. Place the golf hat in a hat case, then place in the dishwasher on a short cycle. Remove and let air dry.
If just a small area of the hat needs cleaning, such as the sweatband area, it is best to wash the area by hand. Mix a mild solution of warm water mixed with a few drops of laundry detergent, then dip a toothbrush or cloth in the solution, and rub over the area that requires cleaning. Repeat as needed until the hat is cleaned to your satisfaction, and allow to air dry.