"Invention Intervention" is a Joker vs. Joker Challenge in the Season Two episode Human Pinata (Murr vs. Q) and Season Three's Look Out Below (Murr vs. Sal). They are in a focus group with 5 people voting for who has a better invention idea. Whoever gets the most votes is the winner.
Human Pinata: Murr vs. Q
Murr wants his invention, the Self Destructing pregnancy test to have more votes than Q's Waterproof Bread. He claims that after you use it, the pregnancy test will explode. It is later proven in the debate that it doesn't self-destruct.
Q created a bread that is waterproof and has a chemical to make it that way. According to Q, it isn't FDA approved yet. Murr dips Q's bread in water and it proves that the bread isn't waterproof at all. However, he is the winner with 3 votes, whereas Murr got 2. Interestingly, all the people who voted for Murr's idea were male and everyone who voted for Q's idea were female.
Look Out Below: Murr vs. Sal
This was the third and final challenge in this episode; a Double-Down Challenge between Murr's CanTenna and Sal's Forty-Seven Hour Energy Bar. Murr lost the last time and hoped he'd win this time around, but history repeated itself because he had one hand raised for his product whereas Sal had three.