Generally, some chemicals do stain the bathtub if they are not used properly. Take note that a chemical with strong cleaning properties can do more harm to your bathtub than good if they are not properly utilized. Make sure to read the label and follow the instructions on how to clean bathtub when using these chemicals. Bleach, powdered cleansers, and acid-based cleaners are examples of chemicals that can stain and do damage to your bathtub.