This is possible by sticking the empty box first inside the bottle and then the cards, 1 by 1, then seal the box with a seal... I don´t know you guys but that´s how I made mine
If you watch the video in the IllCenter, you will learn that the key is turned back to normal after the trick is done, because in Kevin Parker words, you can´t give them the key if it´s bend, so you turn it back to normal.... check it out