Our Washing Machine Tub Cleaner Contains Sodium Bicarbonate And Citric Acid. It Can Penetrate Into The Interior Of The Washing Machine And Bathtub, Effectively Removing Dirt Residues. Remove Odors And Keep The Washing Machine Clean And Fresh. Its Usage Method Is Very Simple: 1. Pour This Product Directly Into The Drum Of The Washing Machine. 2. Add Normal-Temperature Water To The Highest Water Level, Start The Washing Machine And Run It For About 5 Minutes To Ensure That The Laundry Detergent Is Completely Dissolved. If The Dirt Is Severe, It Is Recommended To Soak It In Warm Water At 40C To 60 C. 3. Press The Pause Button To Soak. It Is Recommended To Soak For 3 Hours For The First Use. When The Dirt Is Heavy, It Is Suggested To Soak For 5 To 8 Hours For Better Results. After Soaking, Rinse Once According To The Daily Standard Mode Of The Washing Machine (Wash - Rinse - Spin) To Thoroughly Clean The Water Tank Of The Washing Machine. And It Can Quickly Dissolve In Water, Efficiently Penetrate Dirt, And Keep The Washing Machine Tank As Clean As New.