Tank derusting

Don’t think has been covered anywhere, so the question is , What is the best method of derusting a steel petrol tank? Electrolysis? Vinegar? Proprietary solutions/kits? or Something else?
Anyone care to comment/share their experience?

I have a friend that swears by filling it with old nuts and bolts and strapping it to a vibrating table!

I have bought a litre of Deox C that was recommended by someone on here recently. I intend to use it soon and will report back.

I did my little Ducati tank with electrolysis. Washing soda from Wilko, battery charger and some strips of steel. I’d say it’s slower than the acid-based methods (vinegar, molasses etc) but doesn’t remove any metal.
But, get as much loose rust out as you can first. Fill it with nuts and shake it about. Wrap in a blanket and put in your cement mixer if you have one.
Ian