Use a Pumice Stone for Remaining Stains (Contextual Step)

What happens here

Although not visually demonstrated in the provided video, if any extremely stubborn hard water or mineral stains remain, a pumice stone is an effective tool to remove them without damaging the porcelain, provided it's used correctly. Moisten the pumice stone and the stained area with water. Gently rub the pumice stone over the remaining stains in a circular motion, applying minimal pressure. The fine abrasive quality of the pumice stone will help lift the deposits. Regularly check your progress and avoid excessive pressure to prevent scratching the porcelain surface. Rinse the area frequently to wash away loosened debris.

Goal: For any hard water stains, rust rings, or mineral buildup that persist after chemical treatment, a pumice stone can be employed as a gentle abrasive. This step is not explicitly shown in the video but is a key part of the described method.