Soaking brass in a vinegar solution is a bad idea. If left in the solution very long, the acid will leach the copper out of the brass, causing the brass to become brittle.
I have heard that, I do not believe it but I have heard that. There should be a discipline among reloaders; I use distance, time, weight and percentages. I have cleaned the worst of cases in vinegar. Being a disciplined reloader I use 5% vinegar, when I use 5% vinegar I set a time limit. I limit the time to 15 minutes. The 15 minutes applies to the life of the case meaning I clean the worst of cases one, after cleaning the cases in vinegar I rinse the cases in boiling water. I rinse the cases in boiling water twice and allow the residual heat in the case to dry the case. And then I tumble, cleaning the case in vinegar reduces tumbling time by days and days.
When the case is cleaned in an acid it does not get a time-out because the case is being cleaned in an acid because the acid is not vinegar. Reloaders have too many different standards. That is the way it is when they do not have disciplines.
And then there were the old days. In the old days a reloader did not forget to remove the cases from the acid because there would be no case left in a very short time. Again, I clean the worst of cases in vinegar for 15 minutes, it is not necessary to go the full 15 minutes but I use 15 minutes for the maximum. In the old days the maximum amount of time was 2 minutes. I also cleaned cast iron and old tools in the same stuff.
F. Guffey