How to clean up a greasy, stained concrete floor
If your concrete driveway, carport or garage floor looks like an Indy 500 pit stop, we have a cleaning recipe for you. First, soak up the grease with some cat litter. Cover the area with a generous amount and grind it in with the soles of your shoes. Sweep it up and properly dispose of the soiled material. Next, saturate the area with a cola beverage, working it into the concrete with a stiff bristle broom — but not allowing it to dry.
Once the cola has stopped fizzing, flush the area with clean fresh water. Whiten the gray stain that remains with a solution of one cup of powdered laundry detergent and one cup of liquid chlorine bleach in one gallon of very hot water. Finish the job with a final rinse.