Question about Out of This World

The other day I picked up Out of This World because I thought it'd be a great addition to a show I'm putting together in just over a month. The thing is, sometimes I mess up the Double Lift, and I'm not sure what the issue is.

I thought I might be making a mistake when pushing off the cards for the double, but I don't think that's it since the move itself doesn't seem difficult.

On the other hand, I'm wondering if it could be due to a lack of card spray, and I've got a few other questions:

-Should I apply card spray to the deck that came with Out of This World, or try it with a different deck?

-If I *do* need to apply card spray, should it only be on the backs? And after applying it, how long should I wait? (If waiting is even necessary).

What do you recommend I do?