I have a 75 hp Merc, I use Seafoam all the time, read the can and follow the directions, pour directly into the gas tank. That stuff is great, I use it in all my boats , cars and trucks. It's been around forever.
Running SeaFoam through the fuel system on a regular basis keeps the carbs clean and helps cut down carbon build-up in two stroke engines. It is not a remedy for carbs that are in dire need of rebuilding because they are hopelessly plugged or varnished. Otherwise use it as indicated on the label.
When you say carb cleaning purposes you mean carbon cleaning. The seafoam may remove some deposits in the carb bowl, not that is not it's purpose. Getting carbon deposits out of the combustion chamber and exhaust housing is what it'll do.
