How much time are other members spending to clean/polish brass?
I used to turn the tumbler on when I left the reloading room for the night and come back in the AM to deal with it, or at least, dump the tumbler to separate the media from the cases.
More recently, I got a timer to shut it down after a time, i have it set for 6 hours. A little less electricity and wear and tear on the tumblers.
With fresh or rejuvenated media, cleaning does not take that long but I have found that I get spots on the cases if it sits in an idle tumbler for too long. So, I run the tumbler longer to keep the cases agitating.
Also, I resize and prep cases shortly after shooting so tumbling batches are small, generally, 100-200 cases, sometimes even less. I've found they do not get cleaned/polished as quickly as larger batches. There must be some case to case cleaning interaction.
Resizing and case prep is not a favorite reloading task so I rather do it in frequent, small doses instead of amassing fired cases for a marathon resizing session. I can zip through resizing and prepping cases from an afternoon's handgun shooting in 10-15 minutes or so. Rifle cases take a bit more time.
The cost of tumbling media is quite low. So, it's hardly worth spending much time trying to extend it's life. Run it till it dies then change it. I change it about once a year and I can't remember how frequently I buy media.
This suits my way of life but is by no means the only way to run a tumbling operation.