Locks that work

I've had the mini fahg for about 5 months. Recently it has started getting really stiff when trying to unlock. Is there a particular reason for this? It's rarely in the rain so I don't think it's rust.
I've dripped a bit of wet lube into it. Will this help or was that an awful idea for the internal lock mechanics?

Chung. Just like a car, you need to change the oil, so for a lock it sounds like its time ot change the oil. If you do not have some in your tool kit, go get Finish Line DRY Teflon Lube in the black/red bottle and give the lock some new life. This Finish Line DRY Teflon Lube is going to make that Mini Fahgettaboudit sing. First be sure you clean with a rag any of the old lube dirt and grime off the shackle and inside the deadbolt area. Then lube. Follow up with this every 3 months or so and the lock is going ot function perfectly- Don