Yeah, I don't think there's anything wrong with the "foul stench" line. It's a good zinger.
The other line always gets a laugh because of Mark Hamill's delivery- he sounds like a whiny kid. It's typical of something that a teenager would say to a parent, telling them that they're off to do something constructive (like go to a friend's house to study), when the parent knows damn well that they're gonna go goof off.