What (stored-as-solids) acids/liquids can clean corroded copper?
Per a source to generally clean copper metal surface, to quote:

A few hard rainstorms may clean the surfaces sufficiently to start operations. However, it is always advisable, particularly if the coloring is to be done immediately after installation, to go over the surface with a commercial chemical metal cleaner. Cleaners of the trisodium phosphate type should be satisfactory. Avoid cleaners which leave a coat of oxide on the copper surface.

However, assuming one has already a basic copper carbonate, the application of an acid, like HCl or more friendly acetic acid, is likely suitable, especially with the addition say NH4Cl or NaCl to increase the activity coefficient of the acid (so less strong acid may be employed).
However, a review of the cited source notes that these reagents are the very agents suggested to create a patina coating (which can be characterized as electrochemical based corrosion) occurring in the presence of air/oxygen.
So, do limit air/oxygen exposure by immersing the copper surface to be cleaned in say a HCl/NH4Cl mix.
Also, employing the concept of a sacrificial anode, experiment with performing the latter cleaning in the presence of a more anodic metal (say a small piece of Aluminum metal in acetic acid and NaCl), especially when the requirement of limiting air exposure could be difficult to implement. This may prove to be actually beneficial in avoiding surface
oxidation.