Potassium chlorate isn't particularly dangerous. It's nothing but a potassium atom, a chlorine atom, and three oxygen atoms. Hardly sinister. If anything, it's generous to a fault, willing to give out the oxygen atoms to anything nearby. And the video you watched above is what it looks like when it gives out those oxygen atoms to some red phosphorus.
The mixture is so volatile that most people are cautioned against even trying to stir it. And this is what's on the head of most strike-anywhere matches. It's true that manufacturers add a little sulfur to the phosphorus, but they also add ground glass to the mixture, to give it built-in friction. Hit the match somewhere and the whole thing goes up. Safety matches, on the other hand, have the oxidizer on the head of the match, and the phosphorus on the red friction strip on the side of the box.
Image: Sebastian Ritter