Just relying on a distraction tecnique isn't enough. He needs the skills to be able to work out for himself that the cult's teaching are bollocks. If you don't teach him those skills, Paradise, Armageddon, all seeing gods, fear of apostates and worldlies and all that other crap you exposed him to, will remain unchallenged with god knows what consequenses in the future.
Until he has those skills, he should not have unsupervised contact with any member of any high control group, family, or not.
http://www.amazon.com/Teach-Your-Child-How-Think/dp/0140238301