Dribbling during a Throw In

[Freddy]

Am I reading this whole thing correctly?
After a time-out after a basket, a middle school girl asks me, "Can I dribble before I throw the ball in?" My split-second response, not really knowing for sure cuz I've never faced that sitch before, was, "Sure." She did. The other coach came unglued. Lucky guess on my part. I checked at half-time and consoled myself with the realization that I made the right guess.
Is it not correct to say that rule 9-2-2, while silent on the manner, is clarified by Casebook 9-2-2-D on this situation?
Funny thing was, when the girl began dribbling at her OB position during the throw in (she didn't dribble the length of the endline, which she could have and caused even more confusion!), the opposing team froze, stopped defending totally due to confusion on their part, and the thrower's team was able to get an easy fast break bucket off it.
I mentioned the situation to my son's coach, suggesting he use it tactically if/when necessary. His response was a good one, "I sure would want to let the ref know what I'm doing before the play so he knows not to whistle it a violation. Most refs I know wouldn't know that it's legal." Wise coaching point, it seems.
Am I reading this whole thing correctly???