hey, so i have this kind of capo:

and the screw/bolt device/ mechanism has seen better days. i was thinking about oiling it up somehow, but i wasn't sure what to use. do you recon i would be able to use WD-40 or something similar, or just oil, or this might be stupid, but i was thinking about finger ease? just looking for something that i would be able to wipe clean so as to not screw up my strings/finish....

any suggestions?
It's always best to avoid wet lubricant if you can. It builds up grime and dust after a while which only makes the problem worse.

I'd try to take the thing apart, get it all cleaned out with WD-40, then wipe that off as best as you can and get some graphite in it.
WD-40 does a number of things well, like displace water (which is what the 'WD' stands for) and penetrate well, but it's a piss poor lubricant.

A couple of drops of light machine oil like 3-in-1 oil might work, or maybe even a dry graphite? (You could try running a pencil over the threads and then working the mechanism in and out, it's cheap and quick if it works, and it often does...)
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