'In their face' apostacy doesn't work well. The WT has provided them with coping strategies for it, so you need get cunning if you want to slip one past the goalie.
It's better to have them wanting to answer a question they don't have an answer for, than dusting off their feet and looking for an 'honest hearted' person.
A lot here have talked about having their doubts while in. Calmly raising a doubt to deal with has to be more effective than chasing them off chanting "Get behind me Satan!", even if it is just a doubt they have already been trying to bury. If they do have an existing doubt, why bring up a new one or try to send them off to jwfacts or sickscreams? They'll google them up when they are good and ready. Our job is just to get them ready and let them know that we are there to support them when they realise that the wheels have fallen off jehovah's chariot.
