For matte finishes there are generally two methods to use. Matte type finishes are normally made to absorb lubricant to prevent rusting, so wet the finish with lubricant and let it sit and absorb the lube. Then wipe it off. The other method is one that came out of the desert wars, heat up the outside of the pistol (we generally just left it out in the sun for a few minutes) so that it is hot to the touch and spray down, or wipe down, with DFL (dry film lubricant). The heat opens the pores of the metal and causes it to suck up the DFL, providing roughly the same rust proofing as oil, however, DFL will not attract dust, dirt and grime like oil will. I have used Mili-Tec1 to good effect, but that was what they gave us in Iraq. The are several brands that can be used.