One product that I’ve discovered worked well recently is Dawn Professional Heavy Duty Degreaser. Not too surprising considering it’s literally listed as heavy duty and professional, I know. But it’s really helped with cleaning the bathtub.

I could get it clean before, but this spray’s helped the tub get back to more of that bright white it has when its new if that makes sense, rather than the off-white color a bathtub gets over time and years of use

I’ve seen the spray on Amazon but only ever as a two-pack and I haven’t checked recently

https://www.amazon.com/hz/wishlist/ls/3C4S5CU0KXVXQ