I use the same basic method as mentioned but I use parts wash solvent. Pour a little on and scrub it with a stiff broom, then pour on floor dry and kind of grind it in with your foot. I leave it a day or so and the oil spot is gone. I suppose gas or kerosene work just as good but I hate the smell of gas and haven't had any kerosene around in decades.
When I was in the garage business I used that method for the oil stains and then scrubbed the floor with hot water and powdered Tide. It keeps a garage from getting that old garage smell. The Zep works great too but doesn't smell that great.