I've used it in every single situation that Chie sweeps you and puts Tomoe on you. Just wait til you completely flatten the ground, neutral tech, then push 5A and you'll cleanly smack Tomoe out of it. It only works with characters who have 5F or faster start-up 5As. I've tested it with Yosuke, Chie, Akihiko, and Yu and they were all able to do it.
Not that this would ever happen, but if Chie like, blindly runs toward you after you tech and tries to 5A you, you can use Kanji's 214C to grab her right through Tomoe's pressure. Once again, it's a 5F thing.