Guys, I posted this on another similar thread some time back but it will be quicker to just type it again -
I looked all over for soft enough vacuum cleaner brushes, tried all the stuff you mentioned, and finally bought 4 of the really soft paint brushes in 2" width - then, I took an extra extension wand (1-1/4, not 2") cut it off shorter (leaving the end that the hose plugs into, duh) then I just used black plastic electrical tape and taped the 4 brushes onto the end of that piece (in a square, around the pipe) so that the bristles stuck out past the end of the shortened extension piece - you can cut off the handles of the brushes so it's easier to seal with tape by wrapping it up (tightly) past the ends of the brushes (away from the bristle end) -
this makes a soft (but crude) version of the dusting brushes you can buy.
In operation, you will want to first turn on the vacuum cleaner and trim the inside bristles that get sucked into the hole.
If you are using a shop vac or anything without a true Hepa filter, you can do what I did - I found some 2-1/2" hose at an industrial hose and fitting place locally, and put the shop vac outside, running the big hose to the area of interest - then, I used a reducer down to the "home size", and a regular hose with the "super brush" on the end.
Works great, and has NEVER changed a setting for me. (If your faders are really smooth and easy to move, it probably WOULD move them - you could only vacuum from side to side if it was important not to move the faders)
Necessity is the mother... Steve