How can PET bottles be cleaned for re-use to avoid accidental bacteria growth?

The refilling and re-use of any bottle first requires careful cleaning.  Always use soap or detergent and hand-hot water (up to 60°C/150°F).  Dry thoroughly to make sure it is sanitary and free of moisture, which can promote bacterial growth.   Consumers should avoid re-using any bottle that has been scratched inside, since bacteria can become lodged in scratches.