Patrick, I don't know if it is a resolution, but your post inspired me to do a little more prep on my S II DC Filament Supply board.
My preferred (lazy?) method of tube pin cleaning is to plunge the pins in and out of a magic eraser. I applied it to all the components as I built the board.
Thanks for the motivation and keep posting your progress.
Karl
Ps. While it's true we're not building airplanes or rocket ships, when done right we can sometimes be transported...