If you want to use it effectively and consistently, as in, you want to use it pragmatically in real matches, you're going to need to practice it for a good solid fortnight. The timing is incredibly tricky, but once you get it down, it's second nature. The purpose of the airdodge is to get Ganon as close to the ground, framewise, as he can get, reliably. Once you're at the peak of your first jump, airdodge upwards. As soon as the airdodge frames end, press jump and do a wizkick simultaneously.
Took me hours of frustrating experimentation to perfect it, but it pays off in so, so many ways lol. I now use it as a taunt as well. 8D