How get rid of watermarks on water bottles?

To remove watermarks from water bottles, fill the bottle with a mixture of equal parts vinegar and water, and let it soak for a few hours. You can also use baking soda as a gentle abrasive by applying it to a damp sponge and scrubbing the affected areas. Rinse thoroughly with warm water afterward to eliminate any residue. For stubborn stains, repeating the process may be necessary.