I could'nt get to he first link.(on an iPad) I have set up a 30 gal plastic tank to use the electrolysis. It worked great for heavy rust. Two issues:
1. Rust is only removed from line of site as viewed from sacrificial electrode.
2. Pitting occurs because of no process control. I have used 250 amps down to 2.5 amp trickle chargers.
My favorite method for rust removal is called out in most heavy aircraft SRMs. Phosphoric acid transforms rust into phosphorous and is relitivly safe.
Two sources are sugar cane molasses (bulk feed supply) and Tractor Supply's Milkstone Remover (used to clean the minerals off of milking machine parts) molasses is slower and safer. Part should have heavy rust removed. I use Milkstone remover to remove flash rust on all steel by spraying it on, let it set for 10 min, then rinse with water. I always do this before I paint. Old timers would then put zinc phosphate on steel to etch steel before self etching primer came out.
My other go to when a part is painted with regular paint is zep heavy degreaser. It's basically costic soda (called out in aircraft engine overhaul manuals for cleaning steel engine parts). Don't get aluminum near it! Will remove paint and rust in a day or too. Temps below 70 will make all processes take longer.
