Dear SilkMuse: Bless you, you gave me something to look for. Here's what I found:

Does anyone know whether the word 'halitosis' was indeed coined by the
Listerine folks back in the 20s, as I seem to remember reading in an
essay about marketing and advertising some years ago, or is this the
linguistic equivalent of an urban legend (that perhaps only I am aware of)?

Joseph Pentheroudakis
Microsoft NLP

PS Yes, I do know the word is a neologism derived from Latin
'halitus', "breath".