not sure what you mean, what is the water stain on?...it makes worse stain than just water on cloth... it will make a wood stain that would help cover a water stain on wood--- steel wool, coffee grounds and vinegar. Place a steel wool pad into a mason jar and add about 1/4 cup of usedcoffee grounds and about 1 to 2 cups of vinegar. Close the container, shake the mixture,and let it stew overnight. Open the container and gently mix the stain.here's additional uses for coffee-- https://www.healthline.com/nutrition/uses-for-coffee-grounds#section14
Your coffee may scratch if it is worth that you’re trying to get the stains out of. I would suggest just putting down some baking soda to absorb the moisture and then dust off.