I made mine very first time vinegaroon based on information in this thread. I also could not figure out a proper recipe, so I just put 4 steel wool pads in 2 litres of vinegar. The wool was with soap so I had to wash it with washing up liquid.
Left it for 1 month or even a bit more, and then filtered it. Then left for a few more days with opened lid and filtered again. Here what I got:
I am not sure if it is supposed to be red color but it works perfectly and gives deep black.