Whenever you clean porcelain, cast iron, enamel or acrylic sinks and bathtubs use the "mildest" product that will clean the surface. This practice protects your bathroom fixtures from excessive wear and also protects our environment from abrasive and corrosive products. Abrasive products or harsh chemicals should not be used for cleaning as they can roughen and dull the surface even causing scratches where bacteria can grow which raises concerns about health issues.
Remember that frequent cleaning will eliminate a lot of problems associated with the build up of soap scum, body oils and bath products. For regular cleaning we recommend the use of a gentle liquid dish detergent. Should you need to disinfect the tub or remove stubborn stains try a liquid cleaner and preferably dilute it one part cleaner to three parts water.
When unclogging the drains of sinks or tubs always pour the drain cleaner through a funnel directly into the drain hole. This will protect the enamel surface around the drain from the corrosive drain cleaner.