Looking to see if anyone has ever done this and been successful with this .
I haven't. I would only attempt it if I lived near the departure port, and knew the ship wasn't sold out and my name was already on the list. If ships are not sold out, they are going to cut the prices to fill them before the day of departure.
Most cruise lines have a list of people waiting for last minute cancellations. These often go to employees or vendor employees. I'm sure it happens though. Just not worth it for me to consider. I'd have better odds of hitting a jackpot in the casino.