It's not hard to figure out: microwave oven transformers are generally considered one of the most dangerous things you can find in a household appliance when misused because they put out enough voltage to reliably punch through even dry skin (which is usually a fairly good insulator which mitigates a lot of the severity of most mains voltage shocks), while still able to generate enough current that when it does form a circuit through you it will not only hurt because cause your muscles to tense up rigidly, burn you badly, and depending on how (un)lucky you are, cause cardiac arrest. It also (as explained in the Big Clive video) bypasses the safety equipment in most houses designed to mitigate shocks from mains-powered devices. Fractal wood burning also involves a bunch of salt-water which only increases the risk. "Only one mistake needed to kill you" is not hyperbole (it's possible to survive shocks from MOTs, but it's not the norm).
"Only one mistake needed to kill you" applies to other things we do every day such as crossing the street or driving a car.
I don't understand why the warning videos were banned, and don't know what potentially dangerous practices that the "fractal woood burning" videos show, or what safety practices they omit, but working with electricity at mains voltages or higher obviously requires due care and attention.
When crossing the street, other people in cars don't want to actually kill you, and those crossing are generally aware and cognizant of the danger. The biggest mistake you can make is 'forgetting to look before crossing'; a lot of the time that won't kill you.
The setup here is very different.
The voltages involved in the wood burning process is far outside of most people's familiarity; your intuition for electricity just doesn't apply.
We're not just talking 'mains supply can be dangerous'; electricians routinely work on switches and such without bothering to shut off the circuit (even though this is typically ill-advised). Mistakes with mains, whilst they _can_ kill, usually just result in big bangs and breakers being tripped.
What you think 'protects' you just doesn't; your insulating gloves, shoes, wire covers, even air gaps; they could just fail you, and badly.
Even aware of this, knowing 'touching the probes kills me', a tiny mistake, such as 'brushing my insulated leg on the piece of wood I am working on, easily made despite being careful, has a very high chance of instantly killing you.
The only way I could see to make this process 'safe' is to not be in the same room as the equipment when it's connected to the power.
