Attempt to form a patine super fail

So I since I have two cck 1303s I decided that I would remove the lacquer and finish on one and attempt to force a patina with heated mustard and vinegar. This may have been a stupid error, or me "miss remembering" how to force a patina. I also tried smashed bananas. I left both on for about say 20 to 30 mins each try. The result is the blade is super reactive and massively discolors onions etc. In addition it now seems to spontaneously form rust. Where did I mess this up?

Some soft iron claddings are nigh on impossible to passivate. Sounds like your CCK falls in this category. I once owned a Moritaka which rusted on sight once the lacquer had worn off the kurouchi finish, it was ridiculous. Totally inappropriate for a kitchen knife.

CCKs are notorious for being a pain to patina