You're better off without the tea 92887, there's no telling how it could effect your system. The very thought of having something like that while fasting makes me nauseas and the brain can respond to the taste by diverting blood flow to the digestion system it's just not advisable. Assure them you're fine, offer to send them information on fasting and ask for a cup of warm water instead.

9 days will be plenty long enough. Just do the fast but listen to your body and be prepared to eat before that time if you feel true hunger- a strong desire to eat a single natural food. Your body doesn't care how much it weighs, only that it is a healthy weight and if left to it's own devices it will find the right weight for you.

Good luck and take care,

Andrew.