I agree with Tom, I'm a locksmith (don't ask why, had to get away from my Father In Law when my wife decided to move him in with us) and we use a spray lubricant called "Super Lube Sri-Film" to lube the lock cylinders. This stuff is great, it has butane as the carrier and PTFE as the lubricant. This stuff is slick as a whistle and really makes the cylinders turn very smoothly, I also use it on many other items. Can be used on electronics, anything that slides or glides and a ton more uses. It does leave a white residue after the butane gases off (very quickly too), this is the powered teflon , it can be cleaned up with a Q-tip so as not to be unsightly but this stuff works really well. I agree with Tom McGriel about lubing. You can look this stuff up at www.super-lube.com and possibly find a dealer in your area. This doesn't leave an oily film like WD-40 does after it dries off. Don't get me wrong here, I like WD-40, it is great stuff but here in the Arm-pit of Texas it causes problems by attracting dust and stuff which gums up the works on a lot of stuff but it is still a good lubricant too.
Just a thought, if you can find it, you might give it a try, it comes with a straw for better placement of the dry-film, give it a try, you may find many more uses for it around the house.
Hope this helps,
