My opinion page addressing inquiries concerning clawhammer technique.
*A friendly warning: frailers have a bad rep amongst bluegrass pickers, so you may encounter some animosity when you first show up at a bluegrass jam!
Too many frailers approach a bluegrass jam as if it were an "old-timey" session. They tend to play over the solos when other individual instrumentalists are taking "breaks". Clawhammer pickers have also been known to be too loud while playing backup (bum-dittys).
We've also been accused of not fitting in stylistically with a bluegrass ensemble: Don't take the off beat "chops" from the mandolin players by playing "bum-dittys", that's their territory! Change your style of play (maybe emphasize the "on" beats instead of the "off" beats).
Insensitive playing can quickly make you an unwelcome guest at a bluegrass jam.
That being said...
Then you should feel welcome and be able to contribute a great deal to bluegrass sessions!

Thanks... Mike