I think "or maybe know" lubeing of straight walled handgun cases is not needed in regards of carbide sizing dies. It just doesn't make any difference in regards to making the die last longer, ect.
With that said, if someone wants to spray them with a lube, lube them by hand, wipe them with whatever, for whatever reason, have at it. I also know for a fact it does make sizing easier, no matter what type of lube is used. Heck I believe Peperation H would probably work wonders. I know for a fact dish washing detergent even works and is easily washed off. I will continue to lube my cases, not because I need to but because its easier, and gives me less pain.
After all this is a hobby, so lets do whatever makes us happy!