I moved house! I tried lots of things the most effective was a fluid (from B&Q?) which you put on and it turned to a white powder which could then be pressure washed away. After two treatments with that, it was not quite so irritating - but I still knew it was there. Is it feasible to lift the blocks and turn them over?

It's right in the middle of a 3m wide section so not easy to lift. Annoyingly it's one of the few bits of drive that is not lumpy or sinking 🤦‍♂️

Moving house is a bit drastic though

😉

Managed to clear up engine oil to a pretty good state using a stiff bristled brush and petrol, jetwash, followed by scrubbing with washing up liquid and another jetwash.

Assume it needs a solvent then to be washed away, which solvent depends on if it's synthetic or not maybe?

Internet suggests alchohol, dish soap, washing powder... maybe all of them>?

Isn't it an oil?
Boiling water and washing up liquid.

A few times.

It may have soaked in though - in which case you may be a bit stuffed.

Daz washing powder (or any biological powder). Sprinkle on with a small amount of warm water to activate it and leave working for an hour. The enzymes will nom nom nom their way through the oil. Scrub and jet wash away. Possibly an environmental disaster.

Spill more of it until it looks like a pattern 👍🏼