Helped my oldest boy do an electrolysis science fair experiment to remove rust from steel pieces a few years back. I got interested in this when a friend was trying to figure out how to remove rust from inside an old Harley tank he bought. Used battery charger and plastic tub with 4" steel bar stock left out in the rain for a couple of months. The variable was the types of liquid solutions we used (I guess the dependent variable was the time it took to remove the rust). One of the solutions was washing soda/water mix (different than baking soda--although we tried that too). The liquid that worked the fastest was Pepsi. My thinking was the acidity of the Pepsi was doing something independent of the charge--someone smarter than I may know. But I think I would stick with the soda/water solution if I were trying to do this to something I actually cared about. The metal pieces de-rusted in the soda solution appeared to be in the best shape when finished. Some other solutions worked OK, but not quite as well. Amazing how well this can work. Sacrificial anodes suffered greatly. Unfortunately, so did the positive clamp on the battery charger, but it kept falling down into the solution whenever the cat would try and bat it around. The cat lived through this experiment.