You don’t need to cool anything down. It’s a comment section on the internet, let people say what they want to say, that’s my approach at least. This disclaimer feels like a “it’s just a prank, bro” so you can deflect criticism. I’m sure commenters are aware where they’re commenting, no need to explain the obvious. And if someone comments how the meme is unfunny or anything not favourable, you don’t have to hide behind your disclaimer.