"Everyone in the world uses too much detergent," she said.
Dillahunt, who plays Plimpton's TV husband, skimmed leaves out of the family's pool.
Waberman's parents said they were shocked when their son won the contest.
Elizabeth Waberman, Ben's mom, added that she cleaned the house thoroughly before the TV stars arrived.
"Ben kept saying, 'leave it dirty, leave it dirty," she said, laughing. "I said, no, they're coming with a camera crew!"
Although Plimpton did don some gloves and use some elbow grease on the family's tub, the network hired actual housekeepers and landscapers to give the Waberman home a deep scrubbing.
The one-hour "Raising Hope" season finale is scheduled for March 28.