I finally got around to looking at your posted video's, and it certainly is the way I have been molding flasks (some made of wood) for several decades, with one exception, I have never worked in bare feet or had my body so exposed to molten metal as those who cast metal in Asia.
Of course, if you want to go back 115 years, we were doing it almost the same way. I posted this photo before; OSHA would have had a "field day" if a company poured metal like that today!
In these times when I pour metal, I take the same precautions the big guys do, even tho I have nobody like OSHA to worry about.
Harold is getting ready to lite off his Induction Furnace in a few weeks, and he will produce his molds about the same way those Asians are doing - I'm not sure if he will pour the molten iron with bare feet and a tee shirt on, but one never knows!
Here are the students at a technical high school making up molds in 1977, a scene that can not be repeated today, because most high school shops have long been closed. They are doing things basically the same way as the Asians, but not sitting in the sand with bare feet. For most, it was a wonderful experience.