Is rubbing alcohol virtuous for cleaning my earthen iron? ...

When you buy a bedroom set does it...
Answers:    Spray a piece of rough material (denim is good) beside club soda. Then "iron" the material on the greatest heat setting. This will remove most stains and residue. If you are speaking of cleaning the inside of a steam iron, use vinegar.
Do paints specially desiged to protect interior walls...
It is nontoxic to use on it - depends on what you are trying to clean rotten as to it's effectiveness.
Calcium deposits are not soluble surrounded by alcohol - so no help on those.