Execution over Exercise
No exercise is magic—it will not have the effect you want on lift technique if you don’t execute it well.
A snatch, clean or jerk executed well is more effective at improving technique than any other exercise performed poorly.
The reason we use variations and supplemental exercises instead of just the competition lifts is because they allow us to focus on specific elements by eliminating other complications or distractions, simplifying a larger motion, or assisting in some way to make better execution easier.
Just doing the exercise doesn’t make it effective—you have to intentionally work to execute it as well as you’re presently able to.
If in this technique exercise or variation you’re performing the same erroneous motion that you do in the related competition lift, you’re not accomplishing anything useful—in fact, you’re just getting better at making the same errors.
You won’t execute these exercises perfectly right away, but you need to do the best you can every rep. If it’s really far off, you need to make a change or find a different exercise at least temporarily to reduce the problems until you can improve the most limiting aspects, then progress back as tolerated.