Tuner Grease

So my tuner on my kanilea is getting pretty rough. Ive been changing strings a lot recently and it feels like there's rust or something built up inside. Is there any recommended way to grease it up or clean it in any way?
I just wouldnt want to accidentally use a compount that might damage the finish or something like that. Thanks

Here is a thread on that.

http://www.ukuleleunderground.com/forum/showthread.php?52651-routine-maintenance-for-open-geared-tuners&highlight=tri-flow