See if you have any one that specials in sandblasting, or restoriazation in your area. I think even on a low pressure setting bead bkasting might be too much in a regular blast cabniet. But crushed walnuts and theres something else thats easier on metals are used in more delicate situations. I bet either one of those methods would clean it up. Hate to see ya give up on it. It looks like only surface to me from picture which isn't a big deal. Thats an easy fix. We used to bead blast stuff all the time and refinish. If its deep pitting that's another story.

Bleach doesn't mix well with the newer powdered metals either. One cleaning method been published in several places about knives and wild game recommended a short bleach soak but long enough to work. I found out the hard way 35 Mintues was too long. Been doing it for over 10 yrs and never had an issue. Place I got new knife offered to replace it because that was there recommendation to customers as well. So I picked my tried n true metals and they used knife to remind people the newer steels don't like bleach.