The answer to me is easy. No one cares what is inside as long as it works reliably. Vairagi had his unit for over 8 years with no problems. It does deliver on its promise of cheap Colloidal Silver that saves BIG $$$.
It also delivers on its promise of quality nano sized particles. It did have me stumped for a while as to WHY it worked so well. Vairagi measured a constant 18 volts across the electrodes, then he measured current going up to 7 milliamps. Why wasn't it making silver MUD?
The answer was in the bubbler and there are also some low value resistors and LED light in series with the electrodes to provide some current limits.
The "hospital grade" bubbler was the major reason, “Super-aerating the water prevents excessive electrical conductivity from building up, which in turn prevents additional silver particles from being drawn from the positive silver electrode…” http://www.thesilveredge.com/aboutmicro.shtml
This all clearly works as described because of Steve Barwick's red Laser test: https://youtu.be/IYde8aK-9S4?t=105
The beam is almost invisible in a lighted room, proving nano particle sizes.