"I didn't notice where you were from, but as someone noted, ONE, if you shoot in cold weather, a light lithium grease works best, though even that may slow your action to the point of an occasional jam, found that out the hard way here in Maine, and TWO, yes it will collect dirt and fouling, you "should' replace the grease after each extended shoot.
Personaly, I have removed the grease, and as someone else also stated, listen for the "short" boing of hte spring, I've had people look at me strange when I suddenly dropped the clip to replace it. "Howd you know it was empty???" hehe tell them it just FELT like the right time! :)