I don't know, honestly. I don't trust that this lie detector test is giving us the full picture here. If we didn't ask the right questions, if this isn't all still somehow a test, if someone's being manipulated into genuinely believing what they're saying... I could go on.
Whatever happened in your world to make Castiel agree to this, he needs to have the opportunity to say no now if he wants to. I don't see how we can view the prior consent as valid when this is an entirely different situation. But if he's agreeing to it? I don't know what we do about that.