A, Sit quietly and patiently, for the "plot" is about to be exposed all on it's own and then there will be destruction in the making. Your xh has really lost his mind to even consider your children as slave labor and putting them in a work environment such as that. I think he's the one that should step up to the plate and go work in a factory if he's that all hyped up about the experience. Why it would make a wonderful vacation of all types of learning experiences for him and the ow. Can you just see that?
I think you are doing the right thing be waiting this one out. It's not going to go very far w/the children and you know what? I look for a mutiny by the children and there is no one to blame but himself and the ow.
He lost the "plot" a long time ago and appears to be completely lost these days. What a nut case.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.