I use very very very light grease on the rails of my ccw guns. Oil I use for range time. Grease doesn't leak out into clothes.
I don't own glocks but they are no different in basic lube needs than any other firearm
"Gun control: The theory that a woman found dead in an alley, raped and strangled with her panty hose, is somehow morally superior to a woman explaining to police how her attacker got that fatal bullet wound." — L. Neil Smith
The problem with being stupid is you cannot simply decide to stop doing dumb things...
"I crapped my pants to avoid the draft!!" -Ted Nugent