Ok, here is the "oil stain" I am talking about.
Look under the Jeep and you can see where the concrete is stained from oil I spilled when changing the oil in the diesel truck. Two and a half gallons
of oil spilled on the concrete floor! What a gigantic mess that was. Oil that has been in a diesel engine is as black as ink, even if it has only been in the engine for 3,000 miles, and it was probably the worst oil I could have possibly spilled on the floor.
I used the kitty litter, and it got most of the liquid oil off the floor, but left a slight residue of oil. I then used a product called "Drive Up" that I bought at Auto Zone. It is supposed to remove oil and grease from garage floors, and it did absolutely nothing. Don't buy the Drive Up product, it is a complete waste of money. I then used a small amount of gasoline and scrubbed the floor with a brush, and then hosed the garage out to get ride of the gas smell. Then I used Dawn dish soap and scrubbed the floor again with a brush, and then hosed the garage out again. That was about ten hours ago and the floor is now dry, and has no oil on the floor that I can feel, but the concrete looks like it is permanently stained. Is there any way to remove that stain?