I think I may have just found the answer for my own question.
A post on the Midway site (BTW, the sizer is on sale for 15.99) from a guy in Texas speaks of using bore lube in the sizer on the bullets.
I must confess I am only now getting a feel for how this sizer works. Since my first reaction (apparently an incorrect one) was that the thing only worked with a lube that was not right for BP applications, I didn't even bother to familiarize myself with it. I think maybe I might should take a closer look.
My reading of history convinces me that most bad government results from too much government. Thomas Jefferson