I recommend going as long as your happy doing it.
If your pleased about continuing with the cleanse, happy to make and drink the lemonades, your making great gains.
You can be detoxing and feeling a little rough but still feel good about continuing.
Its when you notice that you've had enough and wish you weren't doing the cleanse. Thats a good time to stop.
The further you go the deeper the cleansing. So it pays to go as long as your happy doing it.
Something else that I have found to be wonderful for cleaning out the skin is the sauna.
Don't know if you have access to one.