This is a lovely effect. There is no question about it. Unfortunately the video production values don't match the effect.
The performance section of the video is mostly zoomed in on the "pearl" and rarely are you shown Peki from far enough back to see his actual working of the effect. While very pretty, this is less than useful in learning the effect.
In the explanation section of the video, while it does show how to attach the pearl, there is no discussion of the proper size or weight of pearl to use. Does the weight of the pearl matter to the effect? It must, but there are no hints in that regard. Another problem with the routine description is that there is no discussion of the clam shell box and the role that it plays in the effect, at the least, you should be told how heavy the box needs to be to provide a suitable anchor. There also is no discussion of how to get the button into your mouth at the start of the routine nor how to clean-up after the routine is over. That is, the very beginning of the routine, the get-ready part of the performance, is not shown, nor is the putting away of the props. While these should be unimportant parts to your audience, they are not unimportant to you as the performer. How do you focus attention way from these necessary bits of skulduggery while in front of an audience, and just what skulduggery do you do? This is not covered in the video.
Finally the video seems to be a sketchy editing from out of a longer and possibly more comprehensive video. Perhaps the missing information is covered there? Unfortunately it is not here.
While these problems are not insurmountable, they detract from the overall value received.
This would be a good $5 physical manuscript and a good $2 pdf. At $20 it is not worth the paper it isn't printed on. Cara Hamilton writes clearly and concisely, but the pamphlet is only 35 pages long (including cover and introductory material) and has a very few useful ideas or bits of advice. I expected a much longer and more detailed work for a $20 pdf. This was not that. I cannot recommend purchase that that price. If the price comes down to $2 or $3, then go ahead and buy it. You won't be wasting your money. But for $20 ... well it wasn't worth that to me.