Things You'll Need
Mildew remover or dish detergent
High efficiency washing machines are designed with a rubber gasket around the door to seal the machine water-tight while it's in use. The rubber gasket can accumulate mold or mildew, causing a musty odor. This buildup is usually caused by detergent or liquid fabric softener residue and a lack of ventilation. Clean the washing machine rubber gasket and air out the machine regularly to keep your clothes and washer smelling fresh.
Turn off the washing machine, and open the door.
Spray a cloth lightly with mildew remover, and wipe the rubber seal along the door to remove any mold or residue. Lift up the seal and check for any lost small items like socks. Wipe underneath the seal to remove as much residue as possible. If you don't want to use mildew remover, dampen a cloth with hot water and apply two drops of dish detergent and clean the gasket.
Dampen a cloth with warm water, and wring it out. Wipe the rubber gasket to remove the cleaning residue.
Dry the rubber gasket with a clean cloth, and leave the door open to air out the machine.