Our washing machine sink cleaner contains sodium bicarbonate and citric acid. It can penetrate the inside of the washing machine bathtub and effectively remove dirt residue. Remove odors and keep washing machines clean and fresh. Its use method is very simple: 1. Pour this product directly into the washing machine drum. 2. Add room temperature water to the highest water level, start the washing machine and run for about 5 minutes to ensure that the laundry detergent is completely dissolved. If the dirt is serious, it is recommended to soak in warm water of 40°C-60C. 3. Press the pause button to soak. It is recommended to soak for 3 hours for the first time. When the dirt is heavy, it is recommended to soak for 5-8 hours for better effect. 4. After soaking, wash once according to the daily standard mode of the washing machine (wash one rinse one spin) to complete the thorough cleaning of the washing machine water tank. And can quickly dissolve in water, efficient penetration of dirt, so that the washing machine water tank clean as new.