The episode: “The Corpse Vanishes,” ep. 105
The riff: Narrated by Crow while the movie’s heroine sleeps in bed, unaware of the menacing Bela Lugosi looming over her.
The explanation: This is a reference to a line from 1970s commercials for Scope Mouthwash. As explained by the commercials, this “pasty film” forms while we sleep and is the cause of “morning breath, the worst breath of the day.” Crow confirms the reference a minute later by repeating the line about “worst of the day.”
Novelty factor: Definitely not the kind of thing I would know off-hand, and fairly obscure jokes for them as well, especially when the name of the product doesn’t actually appear.