I had no idea about the cult around a toy from the 50's; that was quite interesting reading.
It is remarkable that I remember almost nothing about these years but never forgot the little boat.
All experiments to make a real size propulsion that way were in vain, although a few guys wasted money on a patent application. It is of course very tempting to have a propulsion system without any moving parts at all, but even the company Pursuit Dynamics, with UK government funding, never got further than press releases and computer animations, just like EEstor and their ultra-capacitor that nobody ever saw.