I think somebody tried that back in the early '90s, but the folks that make commercials got around it by suing the guy that invented it, & then developed their own technology to override muter doohickey.
Sorta' makes ya' wonder who the V-Chip's really supposed to be protecting.
Wasn't Magnavox Smart Sound? I still think it should be made as an add on and not incorporated into the TV that's a way I think of getting around it. We have the technology.