I agree w/Maxim. You’re currently at 11% and you have 12-weeks to diet. You’ve got the time, definitely, to get down to your 3%. And rather than spend alot of time on the bike, treadmill, whatever you might be doing for cardio; may I suggest you think about HIIT? Try sprints, jump rope - this will help you preserve that muscle mass while you lean up further. And start your posing practice NOW. THIS will help you harden up. THEN you’ll see that the Fat Fast may not be needed or to do as Maxim said, as a “fine-tuner.”
Here's something else to think about: that last week before the show - you're going to drop alot more weight than the previous weeks. Due to the stress, anticipation of the show combined with the daily stresses of life. SO, to avoid this, make sure that by that time, the only "cardio" you need is posing practice. I hope this helps. And let us all know here how you did!