Yep I use the chop with a motion like throwing a baseball - arm ends up extended in the direction that I'm going...AND HOLD pulling through the intersection.

The exagerated move seems to be visiable directions can see it (combined with lights).
---------
While driving, I've seen the tickle fingers and wondered if the guy was a fruit-cake (err sorry tickle finger signalers, it seemed more deragatory less logical to me).