Is there a trick to using Change Scroll/Magic Compact effectively?

[Exactoman]

I finally completed every single Info Book and the only thing between me and the platinum is one more Globegate Skillbook. I've heard mention that using Change Scrolls or Magic Compacts can help get the item you need, but I've tried ten consecutive runs using every Scroll/Compact in my inventory. Is there a trick to it, or is it just completely random?

 

Edit: Well, I kept trying and eventually the book showed up for me. Platinum #100 woooo

Edited September 7, 2021 by Exactoman