Clean detergent drawer
The detergent drawer of the washing machine should be cleaned regularly. If you do not want to do that by hand, and have a dishwasher, it's good!
Simply the detergent dispenser in the dishwasher, where it is pikobello clean, even in places where manual cleaning at least cotton swabs, if not even toothpicks needed.
It is recommended, however, not to choose the hottest rinse, the plastic of the detergent drawer could deform!
Clean drawer and regularly cleaned rubber grommets help to prevent musty smell in the washing machine.