Porcelain and Enamel

Avoid any cleansers that have an abrasive action, such as scouring powder. The easiest way to remove stains is with citric acid or tartaric acid, which you should rinse off carefully afterwards. Limescale can be removed using an old housewives' recipe: "Heat up some household vinegar to around 50°C. Rub this into the limescale. Leave to soak. Repeat the treatment if necessary." It worked then and it works now!