I know exactly what wiring is, but it's not something I've ever used, so will bow to your experience regarding surface finish.

However, it's not a fast process, and isn't going to be faster than a milling machine for surfacing. And that's before you consider any other features that may be getting milled during the same setup.
What people were getting at, is your reply where you're stating methods by making assumptions and without ever having seen the part, or the reasons for the milling.