I strongly dislike this idea- framing all of this in the context of a defense that protects you is setting up the entire Think/Insight/etc. avenue of RP as an inherently dangerous mechanic that you should protect yourself against, and that isn't what this is.
You don't need a new command, you don't need a config. Make it an enchantment that must be worn. That way, if you -want- your thoughts to be heard by anyone OTHER than Celani, you simply need to remove that item.
Call it Mantra that while worn, all thoughts are hidden from view except by the most powerful of Divine.