I actually tend to go for bright and shiny:
a) Facilitates case inspection.
b) Tend to insure lack of stray lubricant, which can drastically increase the force on the breech face.
c) And I just like bright and shiny!
That said, I'd hesitate to use any wax based product, since they tend to be lubricants.
I use crushed walnut shells, and every once in a while I add a very small amount of powdered jeweler's rouge (ferric oxide) (not the wax-based stuff you buy for putting on a buffing wheel). You can buy a lifetime supply of powdered jeweler's rouge for under $10 as I recall.