pickling a crank

I used a big plastic bin 25 gal or so put in 15 gal water then boil 2gal of water and put in a couple cups of washing soda so it mixes up real good than dump it in the tub of water, throw in my part with the neg wire on it and hook the pos wire to a break rotor or large piece of sheet metal and after a while you have to clean the sheet metal because the rust will be pulled off you part and collects on the sheet metal and the process stops working till you clean it off. Cleaning a cage would be a pain.