If you look closely, the tips are all sharp hooks...
For my plan to work using DCM solvent, my flat PC rectangular piece (shown in red in my previous post) would need to lay flat across the ribs with virtually no grit or scratches on the backs of those ribs because DCM doesn't fill gaps. So my concern about using a spinning-hook dental cleaning instrument is that it would basically remove the chrome paint and roughen up the surface of the plastic too, making less surface area for the DCM to do its job. That's my guess anyway.
With that said, I still haven't figured out how to get that chrome paint off cleanly though.