That's funny that the Glock armorer said "No grease on Glocks!" because my dad's brand new G22 was absolutely lubed to the gills with some sort of purplish grease. Even the gun shop owner said he never saw anything like it, and that was right out of the factory sealed box. My G26 had a bit of grease from the factory in the back of the frame where the trigger bar rubs against something or other.
That said, I use a quality oil, currently using Nano Oil since the dispenser is so nice.