Clean

We don't live in a hard water area, but the water isn't super-soft either and we do get some limestone scale build up. My wife spotted that citric acid powder is cheaper than vinegar and has the advantage that it doesn't really smell of anything.I'm going to test it overnight on an unsuspecting porcelain receptacle.

Citric acid is a 100% natural occurring organic acid, but it's not from organic agriculture as the asterisk here indicates if you read the small print on the bottom of the box.