You don't even need to watch the video to know that a claim of 70% savings is pure platinum plated bulls--t and any device that claims to provide it is pure snake oil.
Start with the
Laws of Thermodynamics which tell you that energy cant be created from nothing, and that all lost energy must eventually end up as waste heat.
Therefore that claimed 70% saving must mean that on average, your electrical appliances have an efficiency below 30%. However most modern PSUs have efficiency over 80%, and air heating appliances can have efficiencies up to 100% - as the 'waste' heat is the desired result, so unless you have a house full of valve amps or similar there isn't enough lost energy 'on the table' to get anywhere near a 70% saving.
Then there's the results of waveform distortion on efficiency. The most common waveform distortion - 'flat topping' caused by SMPSUs without power factor correction (PFC) drawing all their current at the peaks of the mains waveform actually increases the efficiency of other SMPSUs as it widens the effective peak so decreases I
2R losses in the wiring, input filter and bridge rectifier feeding the input side DC bus, and in the PFC circuit if present. Therefore claims of general efficiency savings by improving power quality have a fishy smell to start with - like last weeks fish guts left out in the sun!
When all's said and done if you could magically clean up the mains waveform without loosing any energy, I'd be *extremely* surprised to see even a 1% improvement in efficiency, and if the device actually does anything, it will be subject to the same constraints on losses as any other electrical or electronic device, so its likely that its losses will be a few percent of the load on it, wiping out any potential saving immediately.
Its true that way back in the day,many industrial and large commercial power users could make large savings by installing power factor correction capacitors, as traditionally commercial and industrial loads were typically largely inductive (think big motors and choke ballasted fluorescent lighting), and the tarrifs they were on often penalised power factors that were too low (excessive VAR) but nowadays there are very few inductive domestic loads that run for longer than a few minutes, and to meet national energy efficiency targets, most inductive loads will already have power factor correction components internally fitted. Also domestic metering only measures real power, it doesn't measure VAR, so as you aren't on a tarrif + metering that penalises peak VAR the only saving to the user is reduced I
2R losses in the wiring between the power factor correction device and the meter. All I
2R losses upstream of the meter come out of the power company's operating overheads so savings in the distribution network wont save the end users a single cent (though they'll probably make shareholders happy).