There are many witches brews for it
For electrolyte you can use almost any polar soluble compound. Salts, acids, bases. I thought sodium bicarb to be safer, cheaper and not corrosive. I'm sure professional restoring groups have reasons for different material thicknesses, time in salt or fresh water etc.
I used 5 gallon bucket with Sodium bicarb, 12 volt dc battery charger (old one that had buffering capacitors) for anode plate tried copper but copper compounds are sticky so it had to be cleaned too often. Then I got a piece of scrap steel that worked better. Connecting wires are copper.
After electrolysis hand wire brush used. I did not use a carding brush. Too expensive for crud.
I used a wood tongue depressor to scrape of big pieces.
There are many things to preserve with after cleaning. I had never seen it used but I used Thompsons water seal because I had some. It might be better to boil in wax after cleaning but i just did not have time and room. Water escapes through wax.
Makes me wonder if the Hunley submarine has finished its electrolysis. I saw it years ago getting treated.
There are many youtubes on how people do it.