Star San is for sanitizing, so I am not sure about that. I'd recommend going after it with Barkeeper's Friend and a green scrubbie. Barkeeper's Friend contains oxalic acid, which will repassify the stainless steel should it have damage.
bar keepers friend worked very well on this pot. I am just concerned about it all getting washed out. I boiled a small amount of water and it had a thin layer of foam on top of the water. Is this just from the boil or could there be another issue with the pot / BKF still in it. I washed it out pretty darn well. I just dont want to waste a batch of beer due to a bad pot