Citric acid, per se is not that bad; the stuff supplied by the makers of drum tumblers like "Lyman", for instance clearly state on the packaging of the "trial" brew packed with the tumbler, that it contains Citric acid. I discovered very quickly that Brewing Supply shops sell Citric acid powder (for cleaning brewing equipment and hoses) a LOT cheaper than the “fancy stuff” from the gun shop. Like vinegar, it is also a useful household cleaner.
Concentration and "run-time" are important. The Citric acid, in combination with the constant agitation and pin impacts, cleans off the "brown" fairly quickly. A THOROUGH rinse in HOT water removes the Citric acid and other "crud" from the brass and then, depending on the time of year and location, spread the rejuvenated brass out in a cotton sheet in direct sunlight,
I've done many thousands of cases that way since I bought a drum tumbler, so far, so good. I do not want "polished" brass, I want CLEAN, uncontaminated brass.
As soon as they are dry and whilst still warm, the cases go into air-tight kitchen containers with a Silica-Gel dehumidifier sachet taped inside the lid. More than a year later, that brass will still be unblemished, until you start fondling it in the reloading process.
I tend to clean and prep in big batches and store the stuff. Preparation includes inspecting cases for bulges, cracks, neck-splits, incipient head separations, etc, at every stage of the handling process. Bottle-necked rifle brass MUST always be checked for length, and trimmed if necessary, BEFORE going anywhere near a press for filling. Regular use of case gauges and a good trimmer will reduce your need to replace a "bent" rifle or the need to learn Braille and manage a Labrador.
Then, reload in small batches as required. How long does it take to run up fifty rounds of your favourite rifle ammo recipe? If you are loading for regular pistol competitions, and you run a progressive press, it is possible to load a LOT of ammo in an evening; using your correctly-stored, well prepared brass, of course.