Frailing, downpicking, clawhammer, stroke style, etc., are all basically the same idea but often mean different things to different players. I've heard folks refer to the simple bum-ditty pattern as both "clawhammer" and "frailing" and then modify these names when drop-thumbing; "clawhammer" becomes "melodic clawhammer", "frailing" becomes "drop-thumb frailing".
It would be nice to see precise descriptive terms enter into our vocabulary but I believe that "clawhammer" has been associated with the entire down picking style for so long that to use this term (clawhammer) to distinguish "drop thumb" playing from simple "frailing" is probably futile.
"Drop thumb" may actually be a better choice of words than "Clawhammer" when trying to clarify technique. Instead of saying "he frails but doesn't play any clawhammer", I think it would be more clearly understood to simply say "he doesn't do any drop thumbing".
I, personally, use all the terms interchangeably as I don't see much use in trying to lock each down to a specific definition.
When I hear someone say they are a "melodic clawhammer" player (which I'm guilty of doing), what does this really mean? Does it mean they never play a brush? Seldom play a brush? Occasionally slip in a melodic phrase? I don't think so. Does a "Round Peak" player limit themselves by never allowing themselves to explore all the various techniques available outside of their chosen style of play? For their sake I certainly hope not. When I first started learning to play, "clawhammer" was used as the word of choice when referring to what is now called "Round Peak" style. Talk about confusing!
No matter what term you use to describe your style of play, isn't it all really just "down picking"?
Thanks... Mike