A totally idealized image:

In reality, I have found that those little pointy prongs, no matter how much you wiggle them against a very solid cork, only succeed in pushing it halfway into the bottle. If you stop and try again, it gets worse.

I’ve had some occasional success with this tool, but I don’t need this kind of extra uncertainty in my life.

I give it an F for its unreliability. Or mine.

Oh, and regular corkscrews can shred a cork, without even removing it one iota, so they kinda suck, too..