HoldMyBeer as Dumdum said, no is NOT to change the PIN, but also to wipe the device. For reference so you don't accidentally wipe your phone again, here is my Duress setup;
My Duress PIN isn't close to the same as my Unlock PIN, therefore I run no risk as to accidentally typing it in. My Duress Password I created but don't even remember it. Its stored securely away, but if I don't remember it, I won't type it. I just remember my Duress PIN. And like I said, its very different from my actual PIN, so I run an extremely low risk of ever typing it accidentally