I know you're not talking about someone with the initials "DW", because ALL of his lifts are legit! (whole lot of sarcasm there, in case anyone thinks I'm being serious).
That sounds like a good idea, though I can see someone breaking the pencil and saying that it was because he went down all the way to his chest, but didn't bounce.
I think you're right though. If you can control the bar down to your chest, without bouncing, you should be able to stop at the pencil without breaking it.
I might try that Wednesday. I'm starting CW's Waterburry Method and Wednesday is my 10X3 bench day. I've always been critical of other people bouncing weight off their chest, but I've caught myself doing it a couple times.