To be honest, I kind of think the concept is freaking brilliant.
I've used something similar in my parenting bag of tricks, but think this incarnation is about to become a standard in our household. Right next to the 'if you leave your stuff laying around, it will go in a box and you have to do a chore to earn its release' idea.
That's just the way we roll around here.
We believe that there needs to be consequences for behavior and restitution where possible. Sometimes, however, equal restitution isn't possible due to the nature of the crime. But we consider our time pretty valuable, so if we have to spend fifteen minutes sorting out a problem, then the 'restitution' would be something that then saves us fifteen minutes.
And no, I don't think that's inappropriate. Our whole family participates in daily chores because we're a family and all get the benefit of living in a warm, well stocked house, so we all, therefore, participate in keeping it clean and warm and well-stocked. It's a pretty firm PFC (Personal Family Conviction) in our neck of the woods.
The chores that would spring a kid from their bedroom jail, however, are of the 'above and beyond' their regular remit. . .stuff like stacking wood, deep cleaning the kitchen, vacuuming out a car, etc.
And I say again: I think it's a freaking BRILLIANT idea!
(photo courtesy of publicdomainpictures.net and can be found here)