Well, his definition of "long term" (10,000 miles) is not the same as mine. A proper head gasket replacement might well work OK for decades and hundreds of thousands of miles and that is what I would define as "long term".

From what I can see that video is basically in line with what Scotty and others here have said, that it is possible for these sealers to work for while but don't count on them providing a permanent fix. It's not a real repair.

I have personal experience with bars head gasket sealer, to be honest, it worked perfectly for my circumstances. Stopped losing a bunch of coolant and the car runs perfectly. The only thing is like Chuck Tobias says, it probably won't be a "permanent" fix. In my case, I haven't yet ran over 10,000 miles with the sealer in system but so far it turned my car that was a coolant chugging piece bad running car to a nice, smooth car, almost as if nothing happened. If you can't afford to replace head gasket and need your car to run for another couple of years. Then give it a shot.