Seconding stabilisers first, and adding the thing that gets skipped: a lot of people who want lube actually want films.
If your switches wobble slightly — a bit of play in the housing when you press off-centre — that looseness produces a hollow, slightly rattly sound that no amount of lube fixes, because it is a fit problem rather than a friction problem. A thin film between the housing halves tightens it up. Five seconds per switch while you have them open anyway.
On technique, since the failure modes are consistent:
Use much less than you think. The commonest bad outcome is not a bad-sounding board, it is a sluggish one, from too much lube on the rails. A thin haze, not a coat.
Springs are where most of the audible win is and where bag-lubing is genuinely fine. Spring ping is the ringing you hear after the keypress, and it is the noise most people are actually trying to remove when they say they want a quieter board.
Do the housings and stems by brush if you are doing them at all. Bag-lubing whole switches is how people end up with the sluggish result.
Budget it as: stabs, springs, films, then stems and housings — in that order of return per minute. Most people stop after three and are happy.