Bleaching silver with salt?

I was recently e-mailing a man from another country (I am an
American). He said that he bleached his sterling silver with "salt"
and it turned white. Can anybody explain this to me? He said instead
of using acid, he uses salt to clean silver. He just puts it in a
pickle pot, takes it out, and torches the silver until it turns
bright white. The problem is I can’t find this “salt”. I thought it
might be a different term or product in English?