Dampen the sink with water, and sprinkle a light dusting of baking soda over the aluminum marks. The water will help the baking soda adhere to the sink.
Scrub the marks with a washcloth and rinse the sink.
Spray glass cleaner onto the sink, if any marks remain. Wipe clean with a washcloth, and repeat several times until the marks show no signs of improvement.
Fill the sink with enough hot water to submerge the aluminum marks.
Pour oxygen bleach into the water, using 2 tbsp. per gallon of water used.
Scrub the stains with the washcloth once more and repeat until all aluminum marks are removed.