In this activity, The Protagonist must devalue property throughout Stilwater by using a Stilwater Municipal Septic Truck's roof mounted Septic Spray cannon to spray waste all over buildings and people. As with Mayhem, money is earned for destroying property, and a set value goal must be reached in each level.
The Protagonist does not drive the truck, but pressing the Brake pauses the truck along the route to allow more time to spray the nearby properties.
In the Red Light District, Mayor Monica Hughes wants to devalue Ultor's property because they stole her husband's legacy. The driver is Sophie, a french mime with revolutionary rhetoric.
The Protagonist: "You have a lovely office." Monica Hughes: "Please, do you really think I'd meet you anywhere public? Look on the bright side... at least we're not on a boat." The Protagonist: "I'm glad you can joke about your husband's death." Monica Hughes: "I'm crying on the inside, I assure you." The Protagonist: "What do you want?" Monica Hughes: "Justice." The Protagonist: "Then call the cops." Monica Hughes: "I said I wanted justice..." The Protagonist: "Who pissed you off?" Monica Hughes: "Ultor's made fortunes by standing on the shoulders of my husband. The gentrification of Saints Row was first referred to as the Hughes Initiative, then the Ultor-Hughes Initiative, and now just the Ultor Initiative. My husband's legacy has been stolen and if I can't benefit from it, neither can Ultor. I want you to devalue their property."
+The Protagonist: "I'm gonna need the name of the septic company the city has a contract with..."
-The Protagonist: "I'm gonna need the name of the septic company the city has a contract with..." The Protagonist - Male 2: "I'm gonna need the name of the septic company the city's got a contract with..."
Monica Hughes: "Why do you need to know that?" The Protagonist: "You'll see..."
In the Suburbs Expansion District, Javier, an estate agent, wants to bring down property values quickly before attending a party at Stefan's. The driver's name is Tony who works as a sarcastic government garbageman and is a relative of Javier.
Javier: "Listen, we have to make this quick, Stefan is having another one of his soirees today, and I'm not missing his pool boy this year. Here's the deal... I've been tryin' to sell real estate in this area for a month but no one's buying because the property value's too high." The Protagonist: "Whaddya want me to do about it?" Javier: "My cousin runs a septic company, I figure you could borrow one of his trucks, drive around the area, and well, ya know..." The Protagonist: "You really think people are gonna wanna buy houses if the area is covered in shit?" Javier: "It's really hard to find cheap housing in Stilwater..."
— "Suburbs Expansion District Septic Avenger" Cutscene
The Septic Avenger activity is referenced in Saints Row: The Third by TV announcer Bobby when he tells his fellow announcer Zach about his trip to Stilwater. He was driving in a rented convertible when it was hit by septic waste from a passing septic truck.