The way I try to teach this is as follows….
Rather than trying to make the bike picot about the rear wheel, imagine it’s pivot point is the centre of the main triangle.
Thus, as well as (smoothly) pulling on the bars, you want to be ‘ushing’ with your legs to move the rear wheel ‘forwards’.
This gives much more control.
Also, the rear brake is your life line!
The best way to practice is (without spds) just riding along and aiming to ‘flip’ the bike so you have to jump off the back.
Once you can do this with ease, then you just add in ‘control’ and aim to stay on the bike!!
DrP