Apparently they do, and pretty bad. I'm almost positive that I've heard ghouls in Underworld say "Pardon the Smell".
So how do people put up with them? Well, a lot of times they don't. :shrug: I tend to think that's because all ghouls eventually go feral though, rather than the stench.
Not only that but your average wastelander probably smells pretty horrid to. So they don't have much room to talk.