However, the video failed to mention that he had some Sodium acetate on the tip of his finger. You need a seed crystal to start the reaction. Also it is not really solid ice but more of a mush like mud. A way easer way to get instant freezing water is to take an unopened non flavored water bottle and put it in the freezer for between 40-60 min. Then take it out and shake it, hit it or pour it out. The results are very similar.
Just dont eat it! It's concentrated sodium acetate. Acetate is what makes vinegar unique and gives it its smell and sour taste. Vinegar is 5% acetic acid and 95% water but concentrated acetic acid can drill a hole in your stomach and intestines. So yeah, you probably don't want to ingest something that causes pain, nausea, and vomiting.