Sorry, I should have been more explicit with the directions on how to do it! Once you do 2D just start holding diagonal jump until your character jumps. After they jump I let my stick go neutral and then input the airdash. Again, I let the stick go to neutral and finally I input the j.22C. The j.22C will look like you are really low on the screen but you'll still be airborne. If you find that the 214C is whiffing after j.22C you just need to delay your airdash by a little bit (which is why I let the stick go neutral to add delay). LordKnight does the 50 meter combo of it in this video near the end.
Also, you will need to dash after the j.22C before inputting the 214C so you can combo into 2B.
Hope that helps!