Rating: Very good. In the ballpark with commercial cleaners, but few name-brand cleaners got rid of smudges with less scrubbing.
Hazards: Bleach is poisonous, so keep it away from children. It will bleach anything it touches, so use only on colorfast items. Check the solution first on a hidden spot.
Uses: Same as above.
Cost: Less than a penny a gallon (not including water)

2 tablespoons or 1/8 cup liquid bleach
1 quart cold water
Mix in a scrub bucket. Moisten an old cloth with the solution and wipe onto surface. Let stand about 2 minutes and rinse well.