Bricks tend to absorb the oil and whilst you can treat and wash it won't completely remove the stain. Turn the bricks over or buy a few replacements - it's not so difficult to DIY.
Further to previous answer. Last year I treated several red blocks on my drive with Jizer. It looked awful when I poured it on. I left it for about three days, then it rained. Oil disappeared, not even a hint of where it had been.
You can now buy a product in Halfords especially for this problem. Jizer is the cheaper option.