The device I'm currently using is a V 2.5 provari. When I first got it the threads were perfectly smooth but after a month or so of constant use I've noticed that the threads aren't as 'fresh' as they were when I first bought it and it slightly squeaks when changing the battery.
So, I was wondering what substances would be okay to use to re-lubricate the threads. Would any of the following suffice? If so, which one would be best;
Thanks in advance!