I thought the gag involving the Teacher constantly exploding everytime the kids p*ssed her off was quite funny.
First of all, normal-type pokémon are weak against Rock so why on Earth can a Meowth(who happens to be one of the smaller, less powerful normal types) be able to completely smash a large boulder/rock in half. Unless of course it was using low kick which happens to be a fighting attack and in turn would be effective against the boulder, but anyway it's just a cartoon so who cares.
Good episode nonetheless, I enjoyed humor throughout, even if the plotline was somewhat pointless.