[Doug]

I would imagine it would depend on the grease Lindsey, what it as be use for in the past and if there’s any risk of contaminates? I would advise the same as Bagpuss. Get shut of them. I would suggest that you take a couple of photos and try and get the garage owner to cough up a few quid. I would also ask the local environmental Health department to sample the grease to ensure that there are no environment or health and safety risks.