Marble
Marble is being used in more and more homes. Marble  is not a stone, but consists of petrified sea shells (calcium carbonate). Marble can be dissolved easily with a mild acid. Orange juice, grapefruit juice, and lemon juice are high in citric acid and vinegar contains acetic acid --all can etch marble. Alcohol found in hair spray, adult drinks, perfumes, and cologne can dissolve marble.  Some types of marble are denser than others and not all react to acid attack. Ironically, to clean marble the experts say to use a mild acid in combination with a mild abrasive, such as salt crystals. Slice an orange, grapefruit, or lemon  in half, dip it in a plate of salt and rub it onto the marble. Then flood the area with fresh water to rinse. Pat dry with a soft towel.

Ceramic and Porcelain Tile
Ceramic and porcelain tile covered in mineral deposits and soap scum can be effectively cleaned with pure lemon oil (any brand -- not lemonade juice but lemon oil from the skin of the lemon). Never use abrasive scouring powder on tile. Use a nylon scrubbing pad soaked in the oil to get the surface clean. The more buildup, the more scrubbing will be required.

Polished Metal
Faucets, shower heads, etc. should never be scrubbed with an abrasive. Even nylon scrubbing pads can scratch a polished metal surface. Instead, try soaking a rag or towel in pure vinegar. Gently wring out the excess liquid and lay it over the affected surface. Keep the rag wet by covering it with plastic wrap to prevent evaporation. It may take one to eight hours, but then a gentle wipe should make the lime deposits disappear.

Mildew
Both chlorine bleach and alcohol work well on mildew. If these chemicals don't work then you might have algae growing, not mildew. To get rid of algae you will need an algaecide (a pesticide for algae) which you should be able to find where swimming pool supplies are available. To remove mildew mix 1/3 cup powdered laundry detergent and 1 quart liquid chlorine bleach into 3 quarts warm water. Add the bleach to the water first, then the detergent. This is a relatively mild formula but you will want to wear gloves and eye protection and make sure that there is plenty of ventilation. Put this thoroughly blended formula into a spray bottle or pump sprayer and soak the affected area. Continue to re-spray the area, keeping it wet until the black mildew turns white. Then, rinse with clean water and pat dry with a towel.

In the Bath
Put your bathmat in the wash with your towels for efficient two-in-one cleaning. The textured terry cloth towels will rub the bath mat clean.

In the shower: soak a few cotton balls in peroxide and put them in the corners of the shower stall to make it mildew free.

Instant glass shine: Rub a thin layer of lemon oil on your glass shower door twice a month to keep it sparkling.

No more tub ring: Instead of tiresome scrubbing, try covering the ring in your tub with a paste made of hydrogen peroxide and cream of tartar. Let it dry, then just wipe it away.