Sticky Lens Release

I have a Pentax ME with a sticky lens release. It sticks slightly when there is no lens mounted, but when there is a lens mounted it is really hit or miss getting it to release.

When there is no lens mounted I can see the nub raise and lower when pressing the release, and it does not seem to be malformed or damaged.

Is there something I can use to lubricate this button and nub to hopefully make it work better without the risk of getting lubricant on any of the optics?

TIA,
cd

i have a similar probelm, have a sigma 28-80mm for my ME-F, and recently brought a second-hand tele-converter at auction, only probelm is my precious 28-80 is stuck to the teleconverter. Anyone know a lubricant to fix this? my next best option is to (gently) hacksaw through the teleconverter to recover the lens, but i'd rather not.