I still have to get the final twist to work but even getting to this point it's been a pretty messy affair.
brendan - yes, the escapees from the grid are easy to enter but those escaping from the clues into the grid can be anywhere in their entries (at either end or inside).
I think the clues should have been easier for something this complicated (and beware the 'work' - I know it and its strange title helped me, but it could hinder anyone unfamiliar with it).