Best tips for cleaning a bathtub? My fiance is a mechanic so he comes home covered in motor oil so…

Best tips for cleaning a bathtub? My fiance is a mechanic so he comes home covered in motor oil so when he showers it transfers all over the tub and it's hard to get off but I hate that it makes the tub look dingy. I'm pregnant so I can't sit there and scrub with harsh chemicals for long, but I'll make my fiance do it lol.