Any practical whip-saw boys out there ?

No, but I read your post with interest.  I was in Haiti for one to two
months at a time from '74 to '86 when the baby was ousted.  It was a regular
scene in the countryside or at little coves to see men cutting planks.  They
set their rigs in trees.  With the bright tropical light and the high
contrast of the trees' shade the only features you could make out was an
occasional toothy smile and the flash of the white of an eye.  Black
silhouettes in constant rhythmic motion.
Best,
Leland