Sounds like snake oil to me...
Ask them for details on how it works...
The only similar thing i have heard of is a "power factor corrector: or something similar. AFAIK it uses capicitors to even out you power draw, which in turn reduces your Maximum Demand charges (reduces spikes).
But I think MD charges are levied only for indusry.
Only Energy charge is levied for home consumers. That could be different in other states.
Even for industry, MD charge is about 10-15% of the full tariff. And you can probably save around 10% of MD charges with a PF corrector.... So only around 1.5% of the total monthly bill.