"What are you using inside the necks?"

I often use nothing inside, no case is going to get stuck in sizer because of a lack of lube inside the necks. The common idea of cases stretching due to expander drag is a myth, the thin necks will easily expand to let a dry expander out before the thicker shoulder brass will give way.

When I DO lube inside necks - and I sometimes do - it's usually with a bit of graphite added to a plastic pill bottle with a half inch of #9 bird shot; push the mouth of the case into the shot and withdraw it, inside is dry lubed. But, graphite IS messy so I keep a bottle of Windex handy to dampen the paper towel for cleaning both my fingers and the outside of the necks.

I also have and sometimes use the inexpensive MidwayUSA neck lube kit with plastic bore brushes and white Motor Mica. It's clean, but mica isn't quite as good a lube as graphite. Still, mica is really good enough.