I have done this to a 1055 carbon tomahawk but just used boiling vinegar, no need to worry about the handle or the heat treat so I just tossed the whole thing in the pot, boiled it some, turned it off and walked away, came back a few hours later and it was all good, but I did then need to touch up the edge to a mirror finish once more, no it's not consistent colouring but it still looks good and weathered.