I am aware of what is known as the Herxeimer reaction and indeed is the body adjusting to the overload of toxins being expelled and the organs of elimination being unable to cope as well as they should; but given sufficient time, the organs do catch-up with this work and the crises are diminished if not eliminated without further intervention.
A difficult time (as I know myself) but the laissez-faire approach has been considered the best approach by Hygienists in allowing the body to resolve its own issues.
Hydrangea root and cranberry juice would interfere with the work of elimination whilst fasting, and only prolong the issue in the long-term for the complete elimination of toxins to take place.