Having recently bought a fresh bottle of the Neutrogena shampoo I usually use, I was amused to see that the main active ingredient was "2% Neutar". All right, think I -- nice to have a unique ingredient, but it's a bad choice of name: it gives the impression that the stuff is made of coal tar or something. So I look at the fine print, and see that it it actually made of (scanning down the list) -- coal tar.
Okay: props to them for truth in advertising. But I think I was happier not knowing. (Yes, yes -- intellectually, I know that it's used for all sorts of filtering purposes. But the image of shampooing with tar now must be expunged from my brain.)
Of course, then there's the facial cream that msmemory has on the sink, which advertises itself as "Non-Comedogenic". Now, I know what that actually means (having looked it up -- it means "doesn't cause acne"), but my brain insists on parsing that as "won't make people laugh at you"...