I've "heard" that using salt in the cleaning solution can discolor the brass some - but have never tried it. I just use straight apple cidar vinegar - have enough in a bowl to completely cover the cases and let them soak for about 30 minutes, aggitating them every 5 or 10 minutes. Then rinse them well in a bucket of clean water and set out to dry. Depending on your weather and climate, you can just let them sit and dry on their own or place them in a oven on WARM only for as long as it takes, usually 30min or less...............you do NOT want to overheat the brass when drying it as annealing is not what you're wanting to do.
And if you really want the insides of the cases clean, you can run a Q-tip around their insides after you take them out of the vinegar and before you drop them in the clean water.
This actually cleans and shines the cases pretty well..................and you can use the vinegar over and over until it gets too discolored for your tastes.