I seached a bit on YouTube, but couldn’t find this one.
As I remember, it featured a white-coated scientist type guy demonstrating a machine (developed by the US Army Dept. of Chemical Warfare)-which measured how stinky your breath would be. The subject then at a raw onion, and her breath was measures (meter went off the scale). The girl then ate a breath mint, and the test was repeated-no oder this time.
Anybody know what product was being hawked?
Sounds like Certs with Retsyn to me. That commercial is vaguely familiar but I can’t say for sure it was Certs being hawked.
I was wrong. It was Clorets, not Certs.
Certs was “TWO, TWO, TWO MINTS IN ONE!”
(with a golden drop of Retsyn)
~VOW
I read the OP title misspelling as “breast mint”. I think that actually might have a better market. 
A truly atrocious pun on “Fort Knox” presents itself, but discretion and good taste prevail.
.