With Hornady "One Shot" (the aerosol version) I would stack 50-100 cases up vertically, spaced about 1cm apart, and spray from an angle (~45 degrees), in order to get some lube into the case necks. Spraying lightly from three sides would get good coverage.
I haven't seen the aerosol version in Canada for a few years and a call to Hornady revealed that they weren't able to send it here anymore.
However, they were supposed to be replacing it with a pump bottle version. If that stuff is like the Dillon spray lube, it's best to spray your cases laying down on a cookie sheet and roll them around to get uniform coverage. I've never had good success with case neck interiors with that sort of lube though. Maybe there's a trick to it that I'm not aware of.
FWIW, the Dillon lube is simply lanolin dissolved in isopropyl alcohol. It's quite a bit more "wet" (longer) than the old One Shot lube and it's best if it's allowed to dry.