How to Clean a Stained Concrete Floor
Purchase a concrete stain at a home improvement or paint supply store.
For general cleaning (or tougher stains) mix mild soap with cool water. Use a pH-neutral cleaner.
Fill bucket with about 1 gallon of warm water and a small amount of mild cleaner or dish soap. DO NOT use ammonia or vinegar as these may damage the finish!
Although properly sealed concrete floors are stain resistant, if a spill is allowed to remain, it may cause a stain. To avoid this, simply wipe up spills promptly with a damp cloth.
If your floor does have a stain not affected by regular mopping, spray the area with an over-the-counter cleaner such as 409 or Fantastik. Let sit for 20 minutes, and wipe with a damp cloth.
Hot water power washers work best in removing grease and oil stains.
Sources: howtocleanstuff.net, ehow.com
