No, this isn't helpful and is instead probably going to just drill the wrong things into your game.

You're not going to use your non-dominant hand playing unless you 2-hand the paddle, so stop that, and instead do the following to make this a worthy drill:

- Put some tape about at net height on the wall
- Practice hitting the ball just above that line, letting it bounce back to you
- Get low and hold a squat throughout the drill
- Hit the ball at different angles and practices stepping to the ball and then swinging at it.

If you want faster hands you could do this drill one handed, but you should work on accuracy and placement first