Using vinegar as suggested by F. Guffey in an ultrasonic cleaner,
What he meant to say is what he said. He has not gone to using a fluid for cleaning except for the worst of cases. That would be cases have had 20 years + to build up a brown patina. I use a 4 gallon jug that is half full of vinegar. He did not say the jug was plugged in nor did he say it had a handle like an ice cream machine.
He did not suggest vinegar be used. And yes! He placed a time limit of 15 minutes maximum, long before that he suggested a time limit of 2 minutes 30 seconds as a time limit because he was using some nasty stuff. The nasty stuff is the reason he went to using vinegar, the difference? Between the nasty stuff and vinegar? Before he used the vinegar on the cases he could use the vinegar on his salad. The nasty stuff would kill someone.
To speed up the process he suggested stirring.
I have not gone to using a fluid for tumbling but for cleaning the worst of cases I use vinegar, it is cheap and last a long time. Vinegar does not require a power source nor does it require manual operation. Vinegar does work better when stirred, stirring reduces the time necessary to remove patina.
I should not have to explain this to the choir, but stirring cases in vinegar does serve the same purpose as stainless pins. The cases bump, rub and scrape years of petunia from each other, something like scratch my case and I will scratch your case. In the big inning I used a few cases in an experiment, I left a few cases in vinegar as thought I forgot about them; TURN PINK!? Those cases disappeared.
And still I ask ‘What cleans the case? The acid or the pins?
F. Guffey
Then there was the suggestion of using vinegar for cleaning rust off of metal. , He has used some nasty stuff that that would in appearance boil over while cleaning a cast iron pot, spider or skillet and old tools. Vinegar has a more friendly time factor.
Then there is that thing about cleaning with vinegar, if vinegar scares a reloader it is possible to reduce the acid content by adding water. Adding water adds to the time factor.