Do not use scented bleaches. These types of bleaches do not always kill germs and so will not be effective in sanitizing your washing machine.
When asked about the dirtiest portion of the average household, most people would name the toilet. However, a household appliance associated with cleaning can be teeming with more bacteria then the average toilet. Your washing machine can harbor multitudes of nasty germs. Hot water and soap are not enough to kill these germs. Follow a few simple steps to completely sanitize your washing machine.
Wash underwear and diapers in separate loads from your other laundry. This prevents the germs in these types of laundry from contaminating your other clothes and linens. Use the hottest water possible to wash these types of loads and add bleach to diaper loads to help kill germs. Even with these precautions, additional steps are needed to kill the germs in your washing machine.
Empty the washing machine completely.
Set the water temperature of your washing machine to hot. Set your water level to high and choose the longest wash cycle.
Add 1/2 gallon of bleach to the hot water. Allow the washing machine to run through one complete cycle to clean the germs. Repeat this process after every three to five loads of regular laundry or after each load of underwear or soiled diapers to keep your washing machine germ free.