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.

New or a few days old oil stains can be got rid of with its counter part
*petrol* old oil stains can be almost got rid of using petrol over a few
months repeating and scrubbing.
The old oil needs to be revived.

--
Sir Benjamin Middlethwaite