Oil drops on an aggregate driveway can be cleaned rather effectively if you can get to it before the oil has seeped deep into the gravel and crushed stone. These tips are easy for anyone to apply, and the materials for the most part are ones you will likely have in your home.
Any oil or brake fluid spill on a porous surface like concrete or aggregate is much easier to deal with if you can catch it before it has soaked into the surface. If the oil is still moist, try these steps before spending money on professional grade cleaners. These treatments are for treating small spots. You can apply these measures to large spills but you will be more likely to need a professional grade cleaner additionally.
Mix a box of baking soda with a cup of fine grain kitty litter or sand. Blend it well and sift it over the surface of the spill. Do not blot the spill before applying this mix, you run the risk of pushing the oil down into the crevices where it will soak in quickly. Leave the mixture on the spill for at least two hours. When you check it, you should see that the mix is turning darker as it absorbs the oil.
After the mixture has absorbed most of the oil, use a hose to spray it off. Mix a few drops of liquid soap with a gallon of warm water. Slowly pour it over the area; stop and use light circular motions with the wire brush. Be careful not to scrub too hard or you could loosen some of the stones. Continue with applying the soapy water and lightly scrubbing until the water is gone. Again, use the hose to spray off the surface thoroughly.
Use old cloths or rags to blot the area gently. Do not apply heavy pressure. If there is any oil left behind it will push into the surface and allow it to absorb. If you still have any staining after the surface dries, you can use one of the many cleaning products on the market. These are strong chemicals so be sure to follow the manufacturer's directions carefully.
