I have now read the links and they claim that the product is a"Surfactant and Dispersant" I take this to mean that it is emulsifying any water in the fuel with the Fuel, and dispersing both the emulsion and any solid deposits or sludge evenly throughout the fuel, so that the dirt and water is Homogenously distributed in the Fuel.
They don't have ringing endorsements from the Engine Makers, only a declaration that that it does not damage their Engines.
Some fuel additives contain Catalysts, which can help breakdown long chain molecules and improve their combustion vut they do not mention that with this product.
Many years ago there was a machine called a "Vicker's Homogeniser" which was marketed as a replacement for fuel Purifiers, the idea being that it was basically a grinder, raw Bunker fuel was pumped through it, any particles were ground into small enough particles to pass through the fuel Filters and at the same time, they, and any water were thoroughly mixed into the Fuel. The advantage being that what would normally have to be disposed off as "Purifier Sludge" was now burnt, slightly reducing Fuel Consumption and solving the problem of Sludge Disposal.
However, if your Settling Tanks, Fuel Oil Purifiers and Filters are all working properly, I am not sure that there is any need for it!!
It is always better to ask a stupid question than to do a stupid thing.