For energy or any other substance to flow from the unseen to the seen, a certain 'circuit' must be complete. When we understand this, there are some advantages. One is that we address some problems pertaining to the interaction between the seen and the unseen such as the so called 'interaction problems of the soul'.
A 'law' of flux along a complete circuit states: At every region of the circuit, along which substances flow, the total amount of substances comming towards that region must be equal to the total amount of substances going away from that region. (find, for instance 'Kirchof's law'). So the substances actualy must swap rather than simply move away or move in. If the substances in question as those moving to the unseen and comming from there, the flux will not be noticable by merely measuring the amount of the seen matter. Apparently, there will be a 'law of conservation of substance', be it matter, energy, charges, momentum, information etc.