I think all "sales pitches" should include a "disclaimer" statement. His should read something like this.
"I Larry Ginger have only spent approximately 30 minutes operating a Z spray manufactured by LT Rich in a parking lot. These are only my OPINIONS about the Zspray but will be presented as Fact". Take the information presented for what it is worth."
...And, if he really wanted to look out for the welfare of others he could put something like "May cause diarrhea or vomiting if ingested"
"The Poor Fish" circa 1930's: The Poor Fish wouldn't have been caught if he'd known enough to keep his fool mouth shut.