I was turned on to Seafoam a few years ago by a friend who is a life long mechanic. Granted, he's "old school" but he's talented, and a believer. Since we in the midwest have a "bike season", they tend to sit for a few months, unused and in fluctuating temps and humidity. He puts the stuff in first Spring gas for all motors that sit for the winter. I do as well. I also use it if I have an unusual poor running condition when I can't get an answer by doing the usual checks. I use it in all "new to me" gas tanks. I believe it does some fuel system cleaning.
The guy in the video makes some good points, but his goofy jabber doesn't inspire confidence.