it's simply not! Once anything that causes your digestition to be awoken passes your lips, the process is over. Any cleansing ceases. And you'll gain back most or all of your weight loss- AND THEN SOME in all likelihood. Truth be told it's far easier to conduct your Master-Cleanse in semi-isolation, temption is hard.
That said, don't beat yourself up about it. Just try again and stay away from friends and family bearing yummies that think you're a freak for fasting in the first place!