Yes, but even mentioning that I should duct tape the ball to my hand, if it falls out... means that the ball is important to KEEP in my hand, even while already sleeping.
Not just the moments before falling asleep.

And sure, it can be a dreamsign, but if fails to be a unique technique then. It's just a dreamsign that you practice, and cause intentionally while awake.

I was interested in using the technique as an easy way for your senses to activate dreamsigns