I use the 3in1 silicone spray and quite like it.
The stuff works the best after the liquid has evaporated. The thin film that it leaves behind is what you want, not the liquid.
When I lube a cube I take the whole thing apart. I line up the cubies and spray all the surfaces. Then I let them sit for an hour or two, come back, wipe off any excess, and put the cube back together. I usually do this before I goto bed, so when I wake up, the liquid has all evaporated and I don't need to wipe any excess off the cubies.
For my regular use cubes, I usually relube them about once a week. The part that takes the longest is just letting them air dry.
I tried just removing a few edges, spraying it in, working it around, and letting it dry. But the results weren't as good as my aforementioned method. Also, since the cube is sealed up, it takes more than a day for it to dry, as opposed to a few hours.