If you want to try to make "Instant Liquid Sculptures" on your own, you will need to either buy a bunch of Sodium Acetate powder, or you can cut open a Reusable hand Warmer that I have verified to contain a high enough content of Sodium Acetate to make the experiment work.
Here is my list of products that will work and from trusted vendors that will fill the order quickly.

1.
EZ Heat Reusable Hand Warmer
This is the one I used in the video. It will work and is shipped fast. You can also find this at some REI stores and some Sports Authority stores, but I would call them first as they don't seem to stock it much.

2.
Proheat Reusable Hand Warmer
Though I did not use this one in the video, I have verified it also contains a high potency of Sodium Acetate and works well for the experiments seen in the video.
Hope this helps you all find your own sodium acetate.