Thanks for the feedback. I hadn't even considered checking with a gunsmith. There is a shop right in the little town where I live. Maybe I'll pop in with some questions.
I finished my first high carbon knife about a month ago and it's getting a patina very quickly from all the grapefruit and lime I cut. Maybe on that test blade I'll just "forget" to wipe it down for a few hours and see how it does. Is there any advantage that you know of to citrus over vinegar?