The b&q brick cleaner shifted it easily, lots of fizzing and after a swill it was gone, only problem is it was too clean so I gotta clean it all now so it matches lol.
I was getting stains engine and gearbox oil off concrete flagstones can be more porous so harder to shift. the washing powder worked well for me on my concrete might have to try some brickacid though don't know why I didn't think of that when I was attacking my stains
