How long on average do you need to let brass tumble? I got a small Hornady brass tumbler for Christmas and am just getting to use it. (Been working 7 days a week for the last 7 months. No time to reload.) Most of my brass is older and dirty and took all day to clean up. I am using RCBS walnut media with the white polishing powder added. Is there better media? I know I am not over loading it. Only putting about 50 pistol cases or 25 rifle cases in it at a time.
Fill me in on the tricks and things I need to know.

Usualy tumble brass in corn media - three hours and it looks great, longer for old dark stuff.
I plug mine into a timer (like for lamps or Christmass lights, etc.) then I just set the timer turn it on and if I cant get back to it 'till the next day, thats OK

An hour in just walnut,an hour or two in corn with Dillon's polish.Going longer doesn't do anything for me but break down the media.Brass comes out better than new.Interestingly enough,I get better results with alot of cases in the machine than with just a few.