Removing Oil, Paint and Other Concrete Stains Remove oil and grease stains from concrete using TSP and other cleaners http://www.familyhandyman.com/garage/removing-oil-paint-and-other-concrete-stains/view-all
DIY Concrete Cleaner You'll make a paste of 3 parts baking soda and 2 parts bleach. It will be thick and soupy (is that a contradiction? Nah...like pea soup, no?). Grab some rubber gloves and a scrub brush. I made my paste in a shallow glass pie plate (I wasn't sure how bleach & baking soda would react with metal, so I opted for glass to be safe).