Holy cow digger, thos ethings are clean, okay i'll buy one and get aquarium gravel?
Small white aquarium gravel, (I used "natural" so I think that is why I get some of that dark toning), 1/3 full, a few drops of dish washing soap, coins, (separate the pennies from other clad), fill with water to cover.
I weigh the whole drum on a kitchen scale and don't go over 2 3/4-3lbs or you will break belts.
For my real dirty coins, and I dig some of the dirtiest, crustiest coins imaginable, 2 hours gets them spendable clean, 3 a little better, 4-6 gets them to what you see in the pics.
Some guys tumble longer.
Always use the 20% coupon from Harbor Freight, and a couple of times a year they have a
super sale where they really drop prices and you can use the coupon on top of that.
Secthun8 got his double on a super deal at $36.
I have the double tumbler, usually about $90 with no discounts.
http://metaldetectingforum.com/showthread.php?t=62317