Solution
If I have a lot of mixed range pick-up brass, I take a big pail, pour in about five liters of very hot water in it, add two full measuring cups of white vinegar, a tablespoon of salt and a good ounce of liquid dishwashing detergent (sunlight).
I dunk the cases in the pail, swish them around for about five minutes then rinse them with cold water to kill the suds.
When the water is clear, I fill the pail with hot water again, put about two drops of blue dishwasher rinsing agent in it and drain the water. Use of a big colander helps.
I then transfer the casings in a big beach towel, tie up the four corners and make the shells hop in it to drain any remaining water.
I put the cases in a dry place and let them finish drying.
When I clean pistol casings in that way, I always spray a whiff of case lubricant on them to avoid brass galling inside the tungsten carbide sizing dies. It's that squeaky clean!
PP.
