For the whiskers, best to use a chamois soaked isopropyl wipe in one direction - form the PCB base to the ends - to grab any fluff, and then denatured water to clean further. The traces on the fader it-self Windex, then denatured water works very well. Scrub
until lint free cloth is completely clean.
The bushings do wear out. AML in the UK has some, but a trick is to rotate all of them 90 degrees. Dont really need a lubricant but if you insist - I use a Teflon based viscous liquid lubricant. The Teflon gets in everywhere, they feel brand new. The best
is to hand polish th eguide rails first - comepltely disassemble the fader, polish wiht chome polish, then rotate the bushings, and lube. Feels better than new!!