low percentage has three (or more) potential meanings.
1. a shot with a low chance of physical execution.
2. a shot that difficult to execute flight-wise. this is usually due to your choice of line.
3. a shot with an unpredictable/squirrely behavior. this is usually due to your choice of disc.
if you need a shot that turns to the right... but not too far to the right, you can try to eliminate 2 and 3 by either a) throwing a stable to slightly understable disc sidearm hyzer or b) throwing a stable to overstable disc anhyzer.
if you can't do either a or b well, then you have to focus on #1.
It seems like I am having some results on the ruler/dowel rod thing by tightening my grip as my forearm is pointing roughly 90 degrees left of the target and extending my wrist/thumb to point between 45 and 60 degrees closer to the target than the forearm. I have not tried throwing the ruler yet. Might have to wait until the wife is out of the house for that
. It seems like doing this I can get the "pft" sound rather than a "whoosh." I am going to continue doing it and see what happens.
focus more on making the pfft AFTER your hand passes the right edge of the body. it sounds like yours is happening way too early. the "ideal" position you will find at the end of the pfft is probably going to be forearm pointed like 30-40 degrees left o the target and the end of the rod pointed at the target. the fact that you have figured out that your wrist must break backwards in order to get the pfft means you are more than halfway there.