Hmm just saw this. Have you tried @JoeCrowe approach with the pure sulfur?
I’m giving it a go. I haven’t seen it on my plants, but I received a clone that was infected, so Im treating all my plants as a precaution since it’s in my house. All blooming plants are now getting weekly canacontrol treatments until im sure it’s not spreading.
Though I keep bonsai moms, so it was easy to cut them back and cover them too to bottom and underneath every leaf.