Dry fasting is still water according to thirst. If you're thirsty drink up, or sip or take spoonfuls out of a glass until you're not thirsty anymore. :) They say that under 'normal' conditions the body can dry fast for 7-14 days. Normal is relative though, the main things to consider from my experience are- how hydrated your body is to start with, being on a raw diet makes a big difference to how hydrated you are- how hot and humid the weather is- and how much exercise and sweating you do. If you just lie up and rest in a nice cool airy environment with reasonable amounts of sun each day I've no doubt that 7-14 days would be the average time for a fast to go before water is needed.
I've never been a tea drinker so don't think much more of tea and the nasties in that than I do of those in cigarettes. There are certainly a lot more nasties in a cigarette but they are still there in Green Tea, or at least in the Green Teas I've seen, I'm sure they vary from brand to brand. Adding anything extra to a fast can only hinder it not help it, in my opinion. The body operates in healing mode at peak efficiency while fasting, the operative word being peak, there isn't any way or need of making it more efficient.