Saturate the stain with liquid detergent. Scrub it vigorously with a scrub brush.
Rinse the soap away with a hose.
Allow the area to air-dry, then check on the stain. If it is still there, repeat the scrubbing and rinsing.
Moisten the stained concrete, if some of the stain remains.
Sprinkle a generous layer of powdered dishwasher detergent onto the spot. Let it sit for five minutes.
Put on close-toed shoes to protect your feet, then pour boiling water over the stain.
Scrub the area vigorously with the brush.
Rinse the area with a hose. Allow the area to air-dry, then check on the stain. If it is still there, apply more dishwasher detergent and boiling water, and scrub again.
Mix 1 cup of trisodium phosphate into 1 gallon of hot water, if the stain remains. Pour the solution onto the stain, and let it soak into the concrete for 30 minutes. Wet the area with more hot solution, if necessary, to keep the concrete from drying.
Scrub the are vigorously with your scrub brush.
Rinse the area clean with a hose. Allow the area to air-dry, then check on the stain. If it is still there, repeat the application of trisodium phosphate solution.
Saturate the stain with a commercial automotive or kitchen degreaser. Experts at the Mrs. Clean website recommend oven cleaner. Let it sit for 10 minutes. Scrub the spot, then rinse away the cleaner. Repeat as often as necessary.