Scrubbin' Down Under is episode 12b of Season 3 of Rocko's Modern Life.
Rocko becomes a celebrity thanks to a little bit of spinach stuck in his teeth.
At kind of a Lot-O-Comics, a patron asks Rocko if he has another copy of the Funnytime Funnies comic book since he sneezed all over the one he was reading. As Rocko offers the patron a spare issue of the comic, Mr. Smitty orders Rocko into his office. As the wallaby enter his boss's office, Mr. Smitty offers him a pink slip, in which a comic-book-society-service-with-a-smile award is being received by the winning employee and that he is to receive the award at the annual banquet on Saturday night.
So on Saturday night, Rocko takes a bath, brushes his teeth, and gets dressed. As he is about to drive to the awards banquet, Heffer tags along and wears one of the salmon from Ed's salmon bushes smeared with car oil as a black necktie in order to look nice at the banquet.
At the Moronic Hall, Rocko starts to become nervous of going on stage to get his award. The nominees for the award are Cosmo Walrus, Joan Crawlfish, Veronica Puverman, and Rocko. When Rocko becomes the winner of the award, he goes on stage to receive his award and tells the joke Heffer mentioned to him earlier. While telling the joke, he flashes his smile, oblivious to the spinach stuck to his teeth, which everyone laughs at. When he returns to his table, still oblivious as to why everyone is laughing, Heffer shows Rocko's reflection through the bowl and Rocko soon finds that the spinach caught in his teeth is the reason everyone was laughing. Mortified, he covers his face with the bowl and walks away.
At home, a frustrated Rocko attempts to brush his teeth, trying to efface the spinach out of his teeth. But the spinach remains, prompting him to use dental floss as he continues to struggle. When the news of his spinach tooth is heard on the news, Rocko attempts to get rid of the spinach with a jackhammer and winds up in the hospital for his impulsive tactic.
While he rests on the hospital bed in a full body cast, the spinach in his teeth grows in size and sucks him into another dimension. Rocko then comes across Clean Gene, the hygiene Genie, who shows Rocko a video of hygiene, which features a kid named Jimmy who failed at a good social life due to his poor hygiene. After the video, Clean Gene checks inside Rocko's mouth to find the spinach stuck between his teeth and uses a running blade to drill his teeth.
Rocko then wakes up minutes later to find that the spinach is now completely out of his teeth. But Clean Gene shows him a picture of his X-Ray, which shows that his brain is dirty, and tries to operate on his head to wash it. Rocko runs away in fear with Clean Gene chasing after him, begging him to come back.