This episode is rather strange, because the setup of the antagonist clearly indicates it's gonna be a bunch of grossout, but then instead he's just lazy. This huge miss of potential for humor is just odd to watch and makes it really feel like the show isn't trying. Some humor at the start does sort of work, but it will also offend many who don't like seeing small children mistreated.
As for the plot itself, it really makes little sense, and gets resolved on a dime. What makes this worse is it ties into the humor problem, because a competition to be as gross as possible would be right up Rainbow's alley and previous series characterization, but instead she basically acts out of character.
Overall, it's the episode equivalent of if your buddy told you he ordered pizza, then once it arrived said it was Hawaiian, then once you bit in you found out that the pineapple, ham, and sauce were all cheese, and it was slightly overcooked.
Overall, it's the episode equivalent of if your buddy told you he ordered pizza, then once it arrived said it was Hawaiian, then once you bit in you found out that the pineapple, ham, and sauce were all cheese, and it was slightly overcooked.