I use to lube before every sort. At one point, though, it seemed to do more harm than good; getting a jam every 500 coins. Now I just do a thorough cleaning of the unit and let it run dry. Few jams since.
I blow my hopper out with compressed air and blow out the eject slot, then remove the slide and clean and lube it about every $200 worth. Works fine.
When I meet the Brinks person that aparently dumped a soft drink in one batch I'll curse them. The coins were so sticky they stuck together and jammed every 10th coin. I finally dumped the whole batch in warm dish water to soak before running the rest.