It's not easy, and it doesn't work on everyone, like most infinites in UMK3. The fact that the ducking LP does like 1.5% damage when DPed makes it virtually impossible to finish out in game. You can either try and do 20 of those ducking LPs, or instead, JK, HK, or run in RH, HK, etc. If you want to practice makes perfect this infinite, it will only strengthen any Kitana player.
In order to do it right, you need to make Kitana duck on the frame that she turns around in the corner, similar to if you do her in-and-out juggle (aaHP on the frame she crosses under holding her facing that direction, making her axis stay behind the juggled character). In this situation, when she ducks and LPs, the contact frame makes them bounce back into the corner because of the 1 frame delay of animation and actual contact. It's a double axis cross up, but it also makes the game think she should be pushed into the corner, which doesn't create ice skate, like it would if she would be pushed out of the corner.
I'm messing around with Mileena right now to see if she can get corner aaHPHP, roll with forward flip into this. Roll out the corner, run in, aaHP roll with forward flip might actually be somewhat useful for her if that can automatically set up the positioning vs some characters.
