congrats on the not having smoked in 6 days! that's awesome.
I've tried juice fasting a few times with the longest being one week. I was successful in losing weight that time and the shorter ones averaged a pound a day. I did not drink that much juice actually. I would probably have a 16 oz glass of juice 3 - 4 times a day max. I thought i would be needing tons and tons of juice but I just found myself bored with it and taking in what i needed to feel satisfied if i got reallly hungry. I kept really busy to keep my mind off of the fast but I also worked out everyday and really intensely. I found I actually had lots of energy and was able to go to the gym twice a day some days.
so i think maybe take in a little less juice and each time you plateau, take that number down more and see if the scale keeps moving down.