I'm looking for a liquid that can remove copper corrosion (oxides and basic carbonates - the black and green stuff) off copper piping.
The corrosion will be located on the inside of the pipe, in hard-to-reach areas, so ideally I should be able to just pour the liquid in, leave it for a while, and just flush it out with water. It will be practically impossible to scrub the corroded areas.
Additionally, the piping is brazed or soldered together with an unknown filler metal.
I've read around, and it seems people commonly use acetic acid (vinegar) or hydrochloric acid for this. Is this correct?
However, I'm interested in if any acids (or other liquids) that can be stored as solids can be used for this instead. Mainly because it's easier to store and transfer solids than liquids. (As far as I'm aware, acetic and hydrochloric acid are only readily available in liquid forms)
Some common solid acids that seem to be effective on rust (iron oxide) that I can buy off Ebay include citric acid, oxalic acid, and sulfamic acid. But will these also be effective on copper corrosion, and keep the byproducts in solution?
Additionally, will I need to use any corrosion inhibitors, to prevent the acid for eating away from the raw metal itself? If so, what should I use, and what acids are they compatible with? I'd like to avoid anything that would leave phosphates/silicates/etc coated on the metal.
TL;DR: What (stored-as-solids) acids/liquids can clean corroded copper, that will leave the byproducts in solution? Do I need to use any corrosion inhibitors?
Note: I do not have access to chemical suppliers, so only things commonly available on Ebay and the like please. Additionally, I do not have fume hood, so no toxic fumes too.