I think the head of household card will be your best bet. They do have tricks to play when an unbelieving husband tries to keep a child from going to the boasting session, and they are all specious. But, if you are really the head, I recommend giving the children equal footing with other opinions including other religions and even atheism.
Trust me, there is nothing to worry about the Devil. What was the Devil's original motive in Eden? To get Adam to wake up and live an independent life without Jehovah Baghead telling him everything to do. Had Adam stayed faithful or Satan not spoken up, life would have been stagnant, with him being told everything to do and not to do. Satan was not required to do that, and it brought extra work and risk from an almighty jerk to do this, but he went above and beyond the call of duty to enhance Adam's life. And he got fired for doing that. Some corrupt boss Jehovah turned out to be--do more above and beyond the call of duty, and get fired for doing it. Some value creator that Almighty Parasite turned out to be.
Now, if Satan was willing to do that for man, then I don't see how Satan could reasonably be expected to turn around and attack people. To me, that would contradict his attempting to set man free from Godly stagnation and oppression. Demons also are trying to set man free from God's influence, allowing man to solve our own problems without some almighty freeloader to take the credit for it. For sure, harassing and attacking people would not fit that purpose. And Satan is not so blindly stupid as the Watchtower Society makes him look.
How afraid of Satan am I? I have numerous heavy metal CDs, including some in my computer. Among them are the dreaded Led Zeppelin songs, included on the box set that is so famous. I have the Rolling Stones' Sympathy For the Devil on my computer, and have no problems associated with it. There is much rap with lots of swearing and blatant drug references on it. I bought a Ouija board the day of the 2006 Crapmorial, and then missed that Crapmorial. I have a house full of Christmas decorations, including the most satanic and pagan images, many of which are still up (and could well stay up all year). I watch satanic videos and think nothing of it. I am able to objectively rate the video game Bulletproof (I faulted it, but only because the graphics make it impossible to see what the fxxx I'm shooting at). And, I have not had any demons attack me or infest my computer to cause any problems.
If anything, I would be afraid of Jehovah, the Watchtower Society, or both. It is obvious that great harm is being done by one or both of those agents, and I suggest doing all you can to make sure your children never choose to become witlesses. Even if it means buying them a copy of Crisis of Conscience and making them read it as a condition of getting baptized.