I firmly believe in the saying, "It takes a thief to catch a thief."
The "awakened" should assist the "sleeping" by helping them to hear the alarm bell gently and gradually.
It took years of repetition of dogmas for the org to perform their mind-changing agenda, so don't expect to find a magic bullet. Just ask viewpoint questions - as you were taught to do in the Ministry School - and wait for the hesitant and mumbled answers which will inevitably not be accompanied by scriptural backing!
For example, "Why does your "faithful slave" teach that foreigners were not participants of the Law Covenant, when God Almighty said that they were?" (Deuteronomy 29:10-15)
If someone just wants to vent and feel as if they've achieved a modicum of revenge by turning up at memorials, conventions, etc. just to cause a commotion, that's their choice. Ultimately, the onlookers will feel vindicated for shunning such "evil apostates" IMO.