I've successfully used Vaseline to preserve various knife blades in storage over the years, without any trouble. I had a thick layer on my BA Golok in the tropics, which dried to a sort of thick, dark grease. When I recently cleaned it off (after about, ahem, 20 years
) the blade beneath was shiny and new looking. So Id say use it for anything going into storage, as long as the blade is clean and dry in the first place.
Ted W