• 1 quart of white vinegar
Fill the empty washer with hot water, as if you're doing a large load of laundry. Add the quart of bleach, and let the full machine run for one minute to mix up the bleach with the water. Open the top of the machine and let it sit, all bleach-y and full, for an hour. At the end of the hour, shut the cover and let the machine run a complete cycle.
When it's done, start again. This time, when you fill the washer with hot water, add the quart of white vinegar to the water and down the bleach channel and let the machine run for a minute to agitate the water and vinegar. After that minute, open the top of the machine and again, let the hot water sit in the basin for an hour before you let the cycle complete.