If your washing machine is smelling worse than your sweaty workout shirt, it’s time to give it a good cleaning. Yes, even washing machines get dirty. Laundry soils, detergents and hard water minerals build up in the washer in areas you can’t see and, over time, they develop an odor. Mold and mildew in the washer lid and the door are another cause of stink. Officials suggest cleaning every six months to avoid any issues.