Learned a hard lesson with this batch of skulls degreasing in a metal bucket that began to rust without me finding out until it was to late. These skulls sat in the rust stained water while degreasing. After they were pulled out and whitened, they still had a yellowish tinge to them. I tried using iron out with some success. I had would let the iron out soak on the yellow stains then mix it with hot water. That worked on one skull but these ones, the yellow won’t really dissipate. Skulls are for customers and hoping to get them back white and rust/iron free. Looking for any suggestions, advice, bone friendly rust dissolvers, or tips please. Is it possible for the skulls that have a light yellow faint to them, to whiten it once again with hydrogen peroxide?