Snake oil? Nah, not even that good!
www.aliexpress.com
A similar device has also been on sale on Amazon US.
I looked at a lot of pictures of both boards and could see no evidence at all that the "capacitors" were in any way connected, no tracks on the PCB at all... I worked in PCB manufacture for a number of years, never seen one with no tracks!

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Smarter Shopping, Better Living! Aliexpress.com
A similar device has also been on sale on Amazon US.
I looked at a lot of pictures of both boards and could see no evidence at all that the "capacitors" were in any way connected, no tracks on the PCB at all... I worked in PCB manufacture for a number of years, never seen one with no tracks!