Not sure which slash you are referring to. If you mean the small ones that a massively holding back Mihawk sent at Luffy, maybe. If you mean the slash from a less holding back Mihawk, absolutely not. Mihawk's slash at WB is so above Smoothie's that it ends up killing her entire family.
Smoothie who had to juice herself up and go beyond her normal capabilities. 'If you giganticize any further you're gonna sink the ship'- Thus implying Smoothie has been growing bigger and bigger, juicing up on her subordinates, until she reached a point where if she grows any larger she'll sink the ship. So she was growing bigger and bigger and yet produced a pathetic, pathetic in comparison to Mihawk's slash, slash. There we have a YC2, as popularly addressed in the community, character growing beyond her normal size and normal power, so effectively at least a YC2++ character producing a pitiful slash in comparison to Mihawk's casual slash.
The slash is barely the size of the Sunny, which is towered by Marine Battle ships
And the Moby Dick is bigger than the Marine ships and Mihawk's slash was bigger. Not even remotely comparable.