User blog comment:DancePowderer/The Smiling Man, Part 4/@comment-10543621-20140424040557/@comment-10543621-20140427230932

Right... Of course.... Sabo... How the heck did I forget him....

Yeah well, he definitely can extend haki through his strings, but that's more for cutting the opponents like what he did to Smoker. I don't think he'd be able to use parasite on a logia even if there's haki. Haki allows contact with the real body, but it doesn't negate the powers. Even if he could 'grab' a logia with his strings, they can just actively disintegrate and escape.

Against a Logia, I think he'd definitely have to use plain ole cutting. Which is why I think Buggy could totally be Doffy's natural enemy if he actually bothered to train himself.