I watched the first video.
It was well made. The technique is not something I have seen demonstrated before, although I'm familiar with the concept. He went into enough detail to make it educational without boring me. I think I could do what he did, because he showed me what NOT to do as well as how it works.
I may try this later today.
One and a half thumbs up! I'd give it two, but I don't have that many to work with.
ETA;
I tried it real quick. The spot I focused on wasn't pure black. I wasn't steady enough to keep the beam focused long enough. The paper got warm, but no smoke. I'll have to try again later.
My life didn't depend on whether or not it made fire, so I lost patience. Probably didn't help that I called my wife into the room to watch my wizardry.