There are great WTF nonsensical advertising that works. But so much depends on execution and being tapped into the meme-mindset. Otherwise it comes off as parody. This one for Dairy Queen is trying to be nonsensical:
This ad doesn't work is because it is a traditional commercial, selling before it becomes a nonsensical commercial, which makes the nonsensical elements seem extremely incongruent. Everyone gets turned off before you can even get to the part about "rainbows on fire.*" [*Which is kind of cool.] But shaving bunnies?
The rest in the campaign just relies on one "punchline" to drive the ad: