let me note the way i cleaned this is absolutely NOT what you are supposed to do. We are moving at the end of the year, and the tub realistically needs replaced anyways so I dont care about any potential damage.

i started with CLR and that did absolutely nothing. Drenched the whole tub then with a bottle of lysol rust toilet cleaner and that removed the orange spots with a scrub daddy. For the remaining I used a whole box of magic erasers.

Could care less if its damaged, anything is better than what it was