Clean and reuse fouled plugs

Have you ever cleaned and reused fouled plugs? My idle mixture was extremely rich and by the time I caught it the plugs were very black but not pitted or anything.
If you do clean fouled plugs what do you use to clean them. Don't want to throw away $175 worth of plugs if they can be saved.
In my lawnmower, sure.
I prefer not to reuse them in carburetor vehicles because they don't clean up completely and become partially unreadable. As others have said.. they'll still work though..and that machine thing from 50 yrs ago would help.