They’re very relaxing to watch after a long frustrating day at work.
I imagine in a pre tech world people would develop a sharp eye for “that looks unusual, let’s take some of that and mess with it and see if it’s useful somehow”.
Imagine if you had 80 years to live and nothing but rocks to play with. You'd get pretty good with rocks and you would be pretty desperate to find something new and interesting to play with.
the clay is far finer than the sand and silt, so it will settle most slowly, and the topmost layer will be mostly clay
some soils deflocculate the clay, so you may need to add a flocculant to get it to decant properly
if your clay is very expansive you may need to add a lot of temper to keep your work from cracking while drying; the good news is that very expansive clays like bentonite are also highly plastic and so can tolerate a higher temper fraction. you probably want the shrinkage on drying (from the fully plastic state to the bone-dry state, though leather-hard is usually a good enough approximation) to be about ⅛. if you have a lot of kaolin you may be able to go lower than that but if it's much more than that you're going to have a really hard time with cracks during the final stage of drying (from leather hard to bone dry)
making things from clay requires a lot of knowledge but fortunately the humans have been doing it for twelve thousand years and so have accumulated that knowledge already
i guess i've also spent a few hundred hours reading about clay (archaeology papers, composite materials papers, textbooks on functional fillers for plastics) and playing with clay, but what i wrote above goes well beyond what i can justify from my own direct observations
(also I think it was a reference to Monty Python: https://www.youtube.com/watch?v=FtHZn5X5bXM)
I would argue that he definitely does. Most of his developmental lineage follows a similar path the the most commonly understood ancient societies. He augments that with modern knowledge, certainly, but is doing most things in a manner “of the time”. He uses tools/technologies from previous videos to build upon the next versus bringing in outside/modern assistance, usually (there have been cases where it’s not completely feasible).
I'm going to go out on a limb here with no real evidence to back me up and say that he probably has his shoes and clothes nearby as well as batteries / solar panels for his camera equipment, including tripod. Probably some modern survival gear (tent?) and food as well.
All this is kept off camera and the actual work of going from scratching sticks on the ground to eventualy working iron seems to be 100% genuine.