I think Quiet Please! is decent strip, it's totally in-character for both of them.
However, the look on Scratch's face in the last panel totally escapes me. I have no idea what that face says -- is it supposed to be a smug "heh!" to the audience? If he's supposed to be breaking the fourth wall, he's not quite making it; he looks a bit cross-eyed instead.
I would have expected some sort of internal celebration on his part, but a little wink to the audience isn't a bad idea either. But perhaps a literal wink could have worked better.
It's been a while since I've done this, but I dusted off the old Photoshop and modified the last panel to attempt to show something that might have worked better:
I'm no Scott Kurtz, but it gets the idea across.
(I forgot I wanted to mention exactly what I did... Obvious: Scratch is now winking and giving a thumbs up. [an update to the update: he's also smiling more clearly.] Perhaps not obvious: I re-positioned his pupil so it is accurately pointed toward the audience.)