I've tried every combination of lubing necks, pads, sprays, Imperial and even q-tips.
Nothing, and I mean nothing, works as well as a nylon brush dipped in fine graphite powder. I dip in graphite, tap off all excess, 2 passes in and out and size. I also have the Imperial dipper, but I don't like the graphite on the outside of the necks.
Another point to be made, polish your expanders, it makes a big difference and stops necks and shoulder stretching.
Bushings also work, but most have an expander anyway, so if you use it, it needs the above, even if it's only pushing the neck out by .002" or less.

Cheers.