Fred wrote:
Is there any way this can be done. For a new oil spot I've used washing
powder and this has sort of worked. However for "old" patches accumulated
over a couple of years what's the best way of getting rid of them? Is it
possible?

I know I could have googled but wary of snake oil products or a product's
effectiveness.


For my block pavers I have applied "Gunk" to the stain with a stiff brush and
washed off
thoroughly after each application ( one usually works). Its been very effective
AFAIC.
Not tried it for concrete but might be worth a try.