Here's two tips involving wax for some household cleaning magic. After thoroughly washing your kitchen and bathroom faucets (a cloth lightly soaked in rubbing alcohol, does the trick), finish them off with a piece of wax paper. The wax will transfer and keep your faucets looking spic and span, resisting water.
We're fastidious when it comes to washing and waxing our car, so we always have some car wax around (carnauba wax, preferably Zymol brand). If you've got frosted glass shower windows, after cleaning them with a vinegar spray, lightly buff them with some car wax for a water stain resisting coat. You can do the same on the sides of a porcelain tub (we don't recommend applying on the bottom unless you want to make your bath tub a slip 'n slide affair). Make Mr. Miyagi proud!