What you describe already has a technical name - acid-to-base, or A2B, extraction. Cyb produced a 'how to' guide to this effect.
So, no, separating the bark is not strictly necessary but there might be reasons for doing so, such as avoiding emulsions if the bark contains lots of very fine particulates.
“There is a way of manipulating matter and energy so as to produce what modern scientists call 'a field of force'. The field acts on the observer and puts him in a privileged position vis-à-vis the universe. From this position he has access to the realities which are ordinarily hidden from us by time and space, matter and energy. This is what we call the Great Work."
― Jacques Bergier, quoting Fulcanelli