Step 1 Clean the Rubber Gasket
Wipe the washer gasket down using a spray-cleaning solution. Bleach-based solutions work well to control and remove mildew, as do vinegar-based solutions. Never mix bleach and vinegar together, however, as they release dangerous toxic fumes when combined.
Spray the mildew cleaner and wipe the gasket clean, making sure to get into all of the hard to reach areas. You can even use a toothbrush to get into the really tricky areas. Once you’ve cleaned the gasket, wipe it dry with a microfibre cloth.