The Toothbrush is a tool in the series. It is used like a mop, and is for scrubbing stains found anywhere. This concept has become a staple in the Chibi-Robo franchise.
The toothbrush is first seen at night, appearing on the floor. Telly suggests that it is able to be obtained and could be used to clean stains. You can earn Happy Points for doing so. There are stains like mud from footprints, pawprints, puddles, tears, and oil.
The toothbrush returns as one of the main cleaning tools in this game. It will be obtained by collecting it from the rim of the sink found in the bathroom. You will most likely need Telly for this access, however. By calling him from the platform, you can fly over to the sink and obtain the toothbrush. The toothbrush can clean substances such as dirt, water, crayon marks, footprints, pawprints, and in a mini-chore, Lucky.
The toothbrush returns in this game. It can be used in Joshy Bear's request to clean the garage. It can clean the multicolored stains around the garage.
Though the toothbrush is not able to be used in this game, it briefly appears in the first cutscene when Chibi-Robo uses it to clean the ship.
Found on the episode "Chibi's First Story / In the Street"