Kevin: I listened to Fiddlin' John Carson's recording too, and I can't make any sense either out of the words you've marked with "????" – however, here's how I hear the last verse:

White gal smell like powder and paint, the yella gal smells the same,
Black gal use no powder and paint, smellin' just the same!

That last phrase, "smellin' just the same" seems a little to un-clever to be believable. I have a hunch Carson usually sang something a little raunchier and he cleaned it up for the recording session.