Fill the cup with boiling water. Heat the water in a microwave oven or in a teapot on the stove. The hot water improves the efficiency of the cleaning process.
Add 1 teaspoon of dishwasher detergent to the water. Stir the detergent in the water with a spoon or fork. Allow the water and detergent mix to soak in the cup overnight.
Dump the water and detergent mix in the sink and place the cup in the dishwasher. Run the dishwasher with its normal detergent and cycle.
Things You Will Need
- Hot water
- Dishwasher detergent
- Baking soda
- Lemon wedge
- Other options include placing baking soda inside the cup and rubbing with a damp rag.
- Place a wedge of lemon in the cup and fill with hot water. The acid of the lemon replaces the detergent used in the previous steps.