OIL ON CONCRETE

Having a son who has a car with an oil leak is no fun, especially if you have a brand new concrete driveway - the concrete doesn't stay new for long I can tell you. Thankfully, he's had the oil leak repaired but I'm still left with an ugly, oily mess where he parks.

I've been asking for ideas on how to remove, or at least lighten, the oil stain and so far this is what I have.

1. Put kitty litter on any unabsorbed oil to soak some of it up. After a few days, sweep that up.
2. Try household bleach first of all and leave for 15 minutes before scrubbing and washing away.
3. If that doesn't work, sprinkle dishwashing detergent on the stain and scrub well with hot water. Repeat this a few times.
4. After using kitty litter and sweeping it away, spread some dry cement over the stain and let it sit for a few days, then just sweep it up. The cement supposedly draws the stain out of the concrete.
5. Sprinkle some dry washing powder over the stain and leave it for a while. Next add a little water to the powder and scrub with a hard brush, leave on for a while then hose away.

Any other ideas would be helpful as I'm going to try all of the above. I'm trying not to use chemicals because any run off would go directly on to a garden bed and I don't want to poison my plants.

UPDATE (November, 2006): Son's car still leaks oil but I've found a good way to almost get rid of the stain. I poured hot water on it, then sprinkled AJAX scouring powder, scrubbed it with a stiff broom and left it without washing it off . Next day, the stain was so light, it wasn't as noticeable. Unfortunately, with the car being parked on that spot all the time, I'll have to keep this up on a monthly basis but at least I've found something that eliminates that nasty black splodge on an otherwise perfect, concrete driveway.