Some interesting tip in this video, on how to use the cleaner - tilting the motor to let it soak.
Other than that - I don't know what the fuss is about. Seafoam cleans. Fogging oil does the same, if you use it like described - spraying into carb, or pouring into cylinder. I don't have a generator, thanks God, solar takes care of that. On my outboard I do this cleaning at the end of season - a little of oil into cylinder, and let it soak all winter. When there is no oil, you can spray WD40 in there, it will do the same. Any oil cleans, hardly a news.
Berryman B12 will clean better yet. Seafoam is a very mild cleaner, it's more a fuel stabilizer, not surprisingly the guy had to pour the whole can into a small single cylinder. B12 is a cleaner, it will clean better. The only problem is that B12 may do this too well, it's hard on plastic parts.