Well, now I don't pick much banjo but I have a long history of pickin' thunmb and index finger, though I'd rather pick with the thumb and the index and middle for blues, but you can really get the thumb and index going and alternating while at it. I do my fake Leo Kottkee that way and some folks believe it.

Once you get it going, it just takes on a mind of its own...

Bobert