I did that to an old crusty bench vise. You don't have to hold the bar, just stick it in the water/washing soda concoction. You need a piece of sacraficial steel and a battery charger. It's super easy.I got the saw almost all back together.. I am working on cleaning the bar. I am using a wire wheel on it. I really wanted to do the washing soda and battery charger trick but can't come up with something to hold the bar.
Sounds like you are looking for a plastic or glass container big enough to hold the bar in the electrolysis solution? Not sure how big your bar is, but some large containers could include: plastic gutter or drain sections from a home store; large Rubbermaid style totes; clear plastic boxes sold at craft stores for storing rolls of gift wrap; a fiberglass bath tub; kiddie pool; a plastic kayak; etc. Or, you could build a shallow frame with 2X4s and line it with several layers of heavy plastic.I really wanted to do the washing soda and battery charger trick but can't come up with something to hold the bar.