sMexy-Blu: There's a better way... Or rather, a different way.
I don't know what they call it, but basically it's a double short hop. You short hop, then immediately use an aerial jump, and use Down air immediately after the second jump. It's completely lagless, and hits a crouching kirby, if I'm not mistaken.
With perfect timing, you can do alot of fun stuff in the air with Dedede.
In a few weeks, I plan to make an instructional video on the subtleties in Dedede's game. All of the different lagless aerials will be included in that, if you want to see.