GM Top Engine Cleaner is far and away much stronger than Sea Foam.
IIRC, Sea Foam is a detergent pack in a light oil. Top Engine Cleaner is a 100% VOC solvent. The MSDS lists "2-BUTOXYETHANOL, naptha, 4-METHYL-2-PENTANOL, 9-OCTADECENDIC ACID" as the components. I'm no chemical engineer, but that all sounds pretty nasty.
As others have said, you can pour it in just as you would Sea Foam or you can mix with gasoline and introduce via the fuel rail with a pressurized cleaning tool. Personally, I've done both with good results from each.
Also, I'd do an oil change after I completed the cleaning.