My Glock 19 is pretty much with me 24/7 I used to use a plastic holster, which had tight spots and wore some of the finish to w ite color, but now in a kydex holster and the finish is great. Because the old spots are being hit by the last holster.
I just wipe off the gun with a cloth, the sweat, I oil every other day or three now, and notice no difference.
SHTF vs TEOTWAWKI you ask? SHTF, just some crap on the ceiling and walls, TEOTWAWKI end of the world as we know it. Orignally made by 9mm/®™©