I'm not sure that a thick filling wax layer could not be built up, but it would likely yellow and come off over time. You can give the matte finish a wetted look with Johnson't Paste Wax, and it's a perfectly good gun preservative, but turning it from matte to satin is about as far as I would expect that to go.
As the others said, under that oxide or black Parkerizing layer (whichever you have) is at least an etched, and quite possibly also abrasive blasted matte steel surface.
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