The Math Tooter
In 2016, toy company Gasbro released a flatulence-focused educational aid called The Math Tooter. The aim was to sell a product that appealed to kids' fascination with toilet humor, while at the same time teaching them basic math skills. It was a small, jolly fat man dressed in graduation attire; when you squeezed him he would vocalize math problems, then end with various puns and fart noises.
While The Math Tooter was a hit with children, sales quickly tanked due to parents being turned off by the loud fart noises and lingering stench. Gasbro CEO Lenard Ripsworth had this to say about the toy: "We all thought The Math Tooter was hilarious, but somehow our designers had baked in the stench of farts into its rubber skin too well; it was stinking up people's houses something fierce. I guess the word eventually got out."
The following year, competing toy company Flattel released their answer to the The Math Tooter, The Farty Smarty. It had internet connectivity and taught children simple programming, but sales were similarly lackluster. These days, both toys go for high prices on Ebay...but potential buyers should be advised about the odor.