I use an even simpler electrolysis set up below primarily for silver coins.
I am using a 3/8" carbon graphite rod for the anode, but people could use steel.
I agree it's best to avoid Stainless Steel, given it apparently releases carcinogenic chemicals during the process. The amounts generated are not doubt small, so I am not sure how much of a real issue it is, but it's one I prefer to avoid.
Ordinary steel works ( initially I used an old HSS drill bit) , but the electrolyte soon transforms into some witches brew of crud....With graphite, cleaning a silver coin, it remains relatively clean through out the process with only the crap off the item you're cleaning entering the solution.
I normally power it connected to a PP9 battery as shown, but the grey connector block (a standard Wago connector) allows me to switch to the USB lead and power it by a USB charger...
All that's missing from the picture is a small container of washing soda that also fits into the box....


The power supply in the video looks excellent if you want to do larger iron objects...I have an old slot car 12v transformer and also an 18v laptop transformer ready to try, but that variable power supply looks better...