I have done this as well and I personally do not recommend it. The reason is the high Sugar content of the lemonade you will drink. I also know at least one lady who got some serious tooth decay problems from the combo if acid and Sugar in the juice.
As a type 1 diabetic, I believe the best liquid cleanse out there is Young's "liquid feast." The reason is he looked at this from the perspective of diabetes, type 1 and 2 and established the guidelines based on this. In short it works. (I'm doing it now)