Exactly right, Phil. If the ball is the correct size for the revolver then it will provide the seal in the chamber, any grease applied over the ball is irrelevant from a chain fire point-of-view. For some reason many people can't seem to grasp this simple concept!
I use .451 in my Uberti, and they don't shave lead, but I loaded one and then knocked it out to see what was happening - there was a pronounced flat band around the circumference of the ball, indicating it was sealing tightly against the walls of the chamber.
As you also point out, any lube applied over the ball is only there to provide a means of keeping the fouling soft. I use wax pills over the powder to do the same thing.
In answer to the original question, there is no "best", it's a matter of what works for the particular individual.