This is currently a minor problem, but it could get worse.
On my Keylab 88, I've started to notice that some of my fader CC values jump. Does anyone know about cleaning this? More curious/worrisome, is that moving one fader will slightly change the value of another. In my case, the very last fader, when moved up and down, ends up adding about +10 CC values to the output of fader 1! This strikes me as some kind of voltage leak, and makes me a bit nervous. This stuff only tends to effect the very edges of the fader run, so it's not a big deal, isn't impeding on my performance at all, but I worry that it could if it gets a lot worse.