Part 40 De-rusting suspension parts which worked better; citric acid or electrolysis? 

Part 40 and it's quite long by my usual vlog standards.
To cut a long and dull story short, I used two methods to remove surface and slightly pitted rust on the trailing arm and associated components on the rear suspension of the Rover;
Citric acid bath using cheap to buy food-grade citric acid which cost £7.95 for
1 kilogram from Amazon or any chemist, Boots etc.
Electrolysis - using an old 12 volt battery charger (actually a power supply for an old Halfords battery booster pack), a bucket, some water, bicarbonate of soda and some scrap steel.
You'll just have to watch the video to see which method won...or use it to cure insomnia.
I've placed it in two playlists - the Rover vlog and my car repair list since the de-rust methods apply to any vehicle - not just a thirty year old Rover.
Any questions, just ask.