Oxpho Blue is very long lasting. I use it by heating the cleaned, degreased part on an old upside-down iron set on about 200 degrees, cleaned off with alcohol. I wear nitrile gloves to keep skin oils off. Then I rub oxpho blue on with a piece of paper towel. The oxpho blue dries really fast and you can put a good thick layer on this way, a little at a time. I "card" the part with dry paper towel until only black is left, and then oil the part. Done. Water will bead up on a 1911 slide I did this way.
NRA for Life
Winchester Canyon Gun Club for Life