Sometimes a gentle cleaning is all that's needed. Try the mildest cleanser, the first one mentioned, then work your way up. Always test any new product in a hidden spot.
Canvas (tennis shoes)
Cleansers: Laundry detergent, powder or liquid; lemon juice
Applications: Sturdy canvas tennis shoes can be machine-laundered. For extra brightening, add lemon juice to the final rinse cycle, then let shoes dry in the sunlight.
Ceramics (teacups, coffee cups)
Cleanser: Denture tablets
Applications: Fill cup with warm water, add tablet, and wait until the fizzing stops. Empty the cup when water is clear. Repeat until all traces of stain are gone. For whitening aged, dingy ceramics, see Earthenware, below.
Concrete (garage floors, sidewalks)
Cleanser: Powdered laundry detergent
Applications: Wet concrete, sprinkle detergent over stains, and scrub with a hard-bristled brush. Rinse well. For oil stains, first soak up oil with an absorbent, such as cat litter, then sweep away, and wash.
Corian (countertops and other hard synthetic surfaces)
Cleansers: Abrasive cleanser, such as Comet; steel wool (without cleanser)
Applications: These synthetic surfaces are extremely durable and can stand up to scrubbing. Use abrasive cleanser on a damp sponge, and rinse. For stubborn stains, scrub with a fine-grade steel wool.
Delicate fabrics (linen, lace)
Cleansers: Mild laundry detergent, such as Ivory flakes; Oxygen bleach; Chlorine bleach (as last resort)
Applications: Hand-launder with mild detergent. If still dingy, soak in 1/2 cup oxygen bleach to 2 gallons water. Treat tough stains on sturdy fabrics with a weak chlorine-bleach solution: 1 teaspoon per gallon of water to start.
Earthenware (white ironstone, unpainted china)
Cleansers: Hydrogen peroxide, commercial grade if available; chlorine bleach (as last resort)
Applications: In a covered plastic container, soak in hydrogen peroxide up to 3 days; check often. For worse stains, use half chlorine bleach, half distilled water, up to 3 days. Follow with soaking in distilled water.
Grout (bathroom tile)
Cleansers: Baking soda; chlorine bleach
Applications: Wet grout, and apply baking soda with a small scrub brush, working quickly so that soda doesn't dissolve and lose abrasiveness. Rinse well. If necessary, spot-treat stubborn mildew with diluted chlorine bleach.
Ivory (piano keys)
Cleansers: Warm water; liquid dishwashing soap, such as Ivory
Applications: Wipe each piano key with cheesecloth dampened with warm water. If necessary, use a drop of mild soap, then wipe again with a clean, damp cloth. Badly stained ivory should be buffed by a professional.
Laminates (Formica countertops)
Cleansers: Liquid dishwashing soap, such as Ivory; baking soda; chlorine bleach
Applications: Follow manufacturer's instructions. Clean with a damp sponge and mild soap; rinse. Treat stains with a paste of baking soda and water, then rinse well. Use diluted chlorine bleach for tough stains; test first.
Leather and suede (upholstery, shoes)
Cleansers: Leather cleaner or saddle soap; lemon juice
Applications: Whiten leather upholstery with saddle soap or leather cleaner; let dry; repeat if necessary. For white suede shoes, remove surface dirt with a stiff-bristled brush, then rub with lemon juice, and leave in sun to dry.
Painted surfaces (walls)
Cleansers: Pine oil cleanser; mild bleaching cleanser, such as Soft Scrub with Bleach
Applications: Wipe down walls with damp sponge periodically; for a more thorough cleaning, use pine-oil cleanser diluted in a bucket of water. If necessary, spot-treat stains with a dab of Soft Scrub with Bleach, and rinse.
Porcelain (sinks, bathtubs)
Cleansers: Liquid dishwashing soap, such as Ivory; baking soda; mild abrasive cleanser, such as Soft Scrub
Applications: Clean regularly with warm water and mild soap. For stains, use a mild abrasive such as baking soda or Soft Scrub on a damp sponge, and rinse well. Avoid harsh abrasives, which can scratch or dull the surface.
Rubber and hard plastic (spatulas, cutting boards)
Cleansers: Liquid dishwashing soap, such as Ivory; chlorine bleach
Applications: Wash utensils in hot, soapy water after contact with staining foods. Whiten and remove stubborn stains by soaking in a 50 percent chlorine bleach and water solution for an hour, checking periodically. Rinse well.
Stone (marble floors, countertops)
Cleansers: Liquid dishwashing soap, such as Ivory; vinegar; marble cleanser, such as Marble Magic
Applications: Some polished marble can be damaged by anything harsher than warm water, so follow manufacturer's instructions. For soap scum in showers, try a diluted mixture of vinegar and water, rinse well.