I've been searching for related topics previously but the search results were only those in the marketplace.. so I create a new one for discussion

Straight to the point.. is this thing works? There are a few liquid products of engine decarbonizer out there.. lots of people bought it but no review given whether it is good or not.. All I see just pictures of cars producing lot of smokes and it claimed to be the carbon and sludges (or it's just the engine decarbonizer liquid itself being...