See Remingtonman . You have to do it fairly quick after the oil spill. Sprinkle concrete powder on the oil and it will suck the oil up. Then just sweep vacuum away.
My outdoor kitchen slab is 22x24. I port a couple gallons on it, use a 30" long handle squeegee to cover the entire slab, then let sit for long enough to finish a pint, then hose off. Don't do this if it's a confined space. Don't do this while wearing your size 16 flip flops either!So what is the process?