My favorite frailer/clawhammer player is Howard Bursen. He has a fine recording on Sandy Paton's very own Folk-Lethargy label . Howard is married to Sally Rogers who is her self a fine banjo player.
Howard plays a drop thumb melodic style that could be argued as not being a frailing style anymore.
I play a knockdown style similar to Uncle Dave Macon's that is as much rhythmic as it is melodic. A very primitive frailing style. Michael Cooney has an excellent method as does Cathy Fink and Cathy Barton.
Publications like Oak's "Oldtime Banjo Tunes" and believe it or don't " Mel Bay's Frailing the Five String Banjo" are good sources for advanced and begiinere tunes.