Thanks Jasok for the kind words. This post was very helpful. The citric acid idea certainly is something I would want to try- though I will use it one something with less critical tolerances than and engine block- just to be cautious.
Another member 69L78 Jeff txt me some pics he used the CA on and it was a huge difference. They were e-brake cables and it was very compelling.
Because of these two, and my own video I decided go try and learn. More. I found d another great video if you want to lightly understand the science of some of these rust removing options.
Keep sharing your experiences. Here is the helpful video I found.