How to Clean Concrete
Pour muriatic acid solution onto the grease and oil stains.
The muriatic acid eats up oil and grease and produces unpleasant odors; so, be sure to keep the area well ventilated.
Wear safety glasses and long sleeves, long pants, and gloves any time you’re working with acids! If you have lung problems, get a helper so that you can cut down on the amount of time you’re inhaling fumes, or have someone else do the job.
Scrub the stains.
Use the old broom to scrub the stains.
Rinse the pavement with plenty of water from the garden hose.
You may want to rent a high-pressure hose. As the acidic water flushes out of the garage, it will clean up the rest of the floor.)