Oh steve, as usual he's more into demagogy then being informative.
First of all, Snake oil is simply anything that doesn't do what it is claimed to do. Cables are not snake oil if they claim to transfer power/signals across distances or look pretty. They are snake oil if they claim to tighten your bass or extend the highs.
Second, the example with the watermelon placed on top of the speakers changing their sound – this is as far from snake oil as can be. Of course putting what is essentially a large water container on top of a speaker will affect it acoustically. It definitely makes a hell of a lot more difference than changing the power cable on the amplifier or putting cable risers.
Third thing, there is a difference between what you can hear and what is actually there. Despite what probably most of the people in the video think, human hearing is inherently flawed, and human perception overall is very unreliable. Even if under precise measurement a thing is making a difference, it doesn't mean that you can actually hear the difference. So I think that the stuff that doesn't work at all (measured to have no effect down to absurdly low DBs) are truly snake oil. Other things that do measure to have an effect but it's smaller than what humans can perceive, are not technically snake oil, because it does work. But the people who claim to be able to hear either one of those are fooling themselves in the same way.
Last thing, I just want to point out that all of the participants there are probably over 50-years-old (some look 70+). With what we know about deterioration of hearing over time, I think we should take most of the opinions there with a heavy dose skepticism.