I'd probably clean it with WD40 then spray on some thick lube as the mechanism has gears in it. I like Superlube spray personally, but there are a lot of cleaners and lubes in the market that will do a good job.

Good luck and let us know how it goes!

I will use a bicycle chain lube like "White Lightning". It goes on wet but the alcohol evaporates and only the lubricant is left behind. It won't attract dirt and dust like most wet lubricants will.

https://www.campmor.com/c/white-ligh...7nXhoCYgbw_wcB

That's a massive Sig ^^^