Nope, it's not possible. Pretty stupid that it's not, but I guess Nintendo didn't realize that almost everyone would rely on it so heavily (with the exception of Isai. Too good).
Practice in endless melees with a level 1 on, and just shffl different aerials on it repeatedly. Don't practice empty shffls, or you'll learn the wrong timing for it. Do it on the CPU. Hell, if you want, make it a human Bowser, make it perma-crouch cancel, turn the damage ratio to 0.5 and give it a 9 handicap, you with a 1 handicap. It won't budge for about 500% damage. Just shffl at your leasure.
This should be in general discussion btw, not the Falcon Boards. Also, you probably could've found the answer by searching for it.