The idea of an out-of-circuit cathode raises interesting possibilities regardless of the outcome of the replicate experiment now in progress.
If the experiment succeeds and the existence of silver confirmed in the product, it might be explained (classically) by regarding the glass vessel as a dielectric, not just an insulator. Dielectrics can pass charge by the polarization of their (immobile) molecules. After all, Kirchhoff's Current Law is not contradicted by air-gap capacitors, electrolytic capacitors or MOSFET devices. If the experiment does not succeed, it still suggests a possible improvement. Why not connect a small silver cathode inside the vessel with a larger aluminum foil on the outside? The aluminum outrigger co-cathode can then shape the electric field, perhaps advantageously, to increase the hydration of silver particulates and decrease their agglomeration. Best wishes!
