What can be done other than Flower stop using it of her own volition? Look, I could say "Flower, you are banned from using it here". What happens when she gets stressed out next time? She either uses it, and the host has to modkill her or undermine what I said, or she doesn't, gets worse, and blows up in another direction. She's going to have to find a way to better channel her emotions if she wants to stop using it, simple as that.