GUEST Sorefingers said "The Clawhammer Thumb should idealy rest ON the B String if learning and 'weave' back UP to get and sound the little G string on the next oddnumbered note - if playing equal division."

For me and for many excellent clawhammer players I know and have played with, this is WRONG. If the thumb rests on the B string, how're you going to hit the third or fourth string as part of the melody? The normal home for the thumb is the fifth string except for drop-thumbing, when it's usually (but not always) dropped to the string below the one you're striking with your index/middle. Note it's called Drop-Thumbing, not Raise-Thumbing - you drop the thumb from it's normal position, you don't raise it.
Cheers
Ray