CD Repair?

I've seen the machines advertised.
The 2 companies I mentioned in my original post (and I'm sure there are others) actually repair the CDs. You send them your scratched CDs, they repair and return them.
Anyone ever used such a service?

I've also seen some serious commercial CD polishing machines.
Doesn't make sense for most of us but I think these services and DVD rental chains may be using them.