That is a creative strategy, but I think that would probably just complicate things rather than saving Ino. I think the infinite tsukuyomi would probably still captivate Ino's body and wrap it up in the shinju. After all, you don't have to be conscious to be captured by this genjutsu as evidenced by the fact that sleeping people were still caught in it. Even if Ino's spirit is elsewhere, Ino's body is still a living entity that still possesses a brain (Ino's brain itself stays within her body, only her spirit transfers), and it still possesses chakara. It can even remotely take damage (if the body that Ino invades takes damage, then so does Ino's body). Keeping all this in mind, I believe that Ino's body, even while she was hijacking Black Zetsu's body, would still be seen by the genjutsu as a living being, and be captured as a result. This would actually make matters even worse for Ino, since once she released her jutsu, she either wouldn't have a body to return to, or she'd just return to a sleeping body (and as a result start dreaming just like everyone under the genjutsu). Her only hope for true survival with this plan of hijacking Zetsu's body, would be to see if she could defeat the caster of the infinite tsukuyomi and release the genjutsu (all while in Zetsu's body). Seeing as how every caster of infinite tsukuyomi was rikudou level, I don't think this is possible for Ino.
