Sorry I didn't get back to you before you soldered CA5668 on the PCB, but it sounds like it working, so that's great.
Sounds like the flux you used may have been a type that is used for cleaning the tip of your soldering iron (to help recondition the tip for "tinning" purposes), but really isn't for use on the PCB. In any case, it is what it is (and there's no point in dwelling on the past).
I am not sure what to use to clean your PCB at this point (i.e. don't want to do more damage than good). I would recommend doing some Internet searches (as that's all I could do). I remember from high school chemistry that the opposite of an 'acid' is a 'base' with 'neutral' being a pH of around 7. Maybe this will help with your searches, but make sure you are also specific as it relates to PCB cleaning. You obviously don't want to create any additional corrosion. And, you also want to be careful not to scratch the PCB to much either. Whatever you find to counteract the acid (in the flux), you will want to ensure it doesn't have a harsh reaction with the materials that make up the PCB. And, when it's all said and done, you want to ensure the PCB is dried off properly because moisture itself can be corrosive as well as not reacting well with electricity.
Here is something I found when doing quick search on "acid base neutralization", that "HCl(aq)+NaOH(aq)⇌NaCl(aq)+H2O(l)" which I think means when combining Hydrochloride acid (HCl) with Sodium Hydroxide (NaOH), the result is Sodium Cloride (NaCl; salt) and water (H2O), therefore salt water. Like I said above, "you obviously don't want to create any additional corrosion" and "you also want to be careful not to scratch the PCB", like with salt water which is corrosive and abrasive.
Do some searching and maybe 73's de Edd can weigh in too on a good solution. Let us know what you discover.
Hey, thanks for the response. I will take a look online and see what works but it makes sense what you are saying about using a base. I appreciate you explaining it.