When I decided to use the phrase "smackdown" in the title, I was thinking in terms of a "contest" between the 2.
However, according to Google, the definition of smackdown is: "a bitter contest or confrontation." Since both sponges are good & effective, I don't think this "contest" is bitter.
That being said, there is definitely a clear winner in this "smackdown". If you want to see which sponge emerges the victor, then just watch the video below. :)