In general, nothing acidic. Acidic items break down and/or etch the sealer. I wrote this article recently for the Virginian-Pilot's Home section; it's a quick read with "rock-solid" advice: http://hamptonroads.com/2010/11/rocksolid-ad...

Hi Elizabeth. A mixture of baking soda and water often works on oil stains and milk. Try a mix of hydrogen peroxide and a few drops of ammonia to remove organic /food stains.

Warm water.....this will work for 95% to 99% of your cleaning needs. If the soiling is heavy with some oil content then add a drop or two of dish soap to the cleaning sponge. Most "cleaners" are not needed and are merely the product of a brainwashed consumer. I have been using warm water on all of my granite for years. Most folks over apply cleaning products to nearly everything...this results in cleaning residues that leave the surfaces dull or streaked

Bed Bath & Beyond has a cleaner.