Scrub-A-Chug is the 14th episode of Season 2.
Chatsworth notices it is getting very dirty inside the underground tunnels. Eddie and Hodge are sent to clean the sludge out of the tunnels, so they refill the Scrub-A-Chug, a piece of rolling stock that brushes the tunnels clean, with soap. Their work is interrupted when they get called away on an emergency. Wilson decides to be helpful by finishing their chores.
Unfortunately, he accidentally replaces the chugwash soap with chugwash sludge when Chatsworth needs a wash and when he tries to clean the tunnels with the Scrub-A-Chug, he ends up making an even bigger mess! Happily, he figures out a way to use the chugwash soap with the Scrub-A-Chug and when Eddie sees the sparkling clean tunnel, he's thrilled.
- Speedy McAllister (cameo)
- Old Puffer Pete (does not speak)
- Olwin (cameo)
This is the first time Eddie wears a visor and ear protectors helmet and uses a chainsaw.
- When Calley pushes the button to go to her underground chamber, her coupler doesn't come out all the way.