In a bit of an appeal to authority, I am a chemist by training and experience. 40 years of bench experience, to be precise. I know a whole lot about how to dissolve stuff that doesn’t want to dissolve.

Your Google search shows one hit for citric acid as a degreaser that is written by someone with a Bachelor of Science degree in public administration. It shows a whole bunch more hits saying basically what I’ve said above. “Citrus cleaners” aren’t “citric acid”. They are lemonene based and usually alkaline. Citric acid is highly acidic.

Vegetable oil is different from petroleum based oils but for this illustration, it is a good model. I’ll assume you are familiar with vinegar and oil for dressing salads. Mix up a batch and see how well the oil dissolves in the vinegar. The oil is nonpolar and the vinegar is polar. They don’t mix. You could substitute the citric acid for the vinegar and they still won’t mix. They are even less likely to mix because citric acid has 3 acid groups per molecule vs one for vinegar. That’s the reason that citric acid is a chelating agent...the 3 acid groups wrap around metals and trap them. It probably takes two citric acid groups to the do the job for most transition metals to get the proper number of electrons to share.

If you are adding soap...probably dish soap...that is doing far more then the citric acid.

I really am trying to be helpful here. People have these elaborate systems for chain cleaning where it can really be simple. Put the chain in about 250 mL (1/2 cup) of mineral spirits in a bottle (large mouth plastic bottles work), vigorously shake it for 30 seconds or until your arm gets tired. Pull it out and let it dry. That’s all that is needed. That’s all that the chain is worth when it comes to cleaning. If you have oil all over the bike, put a little on a rag and wipe away.

Then consider using a lubricant that doesn’t make a mess.