PWM Push-Pull Square Wave w/ Espruino to drive Voltage Multiplier

Because we do not have negative swing like with real AC, the wiring is not as usual: What usually is connected to Ground (GND), has to go to 3.3V

Ahh, yes - I've only used voltage multipliers with digital circuits so I never thought to mention that :)

What about using schottky diodes? By getting the diode voltage drop down to 0.3v instead of 1v you could make the voltage multiplier substantially more efficient...