Clean cases are much easier on the dies.
I use the vibrating type vleaner rather than a true drum type tumbler.
I use Dillon charging media in ground walnut hulls.
Don't buy the media from the LGS or big box stores.
Go to a pet supply store and buy a 16/20 lb bag of the stuff they sell for the bottom of bird cages.
I get mine at PetSmart.
It is a LOT cheaper than buying charged or un-charged media elsewhere.
Some times you can find the same thing at an outdoor supply place. It is sold for flower gardens.
It is ground up walnut hulls and that is what you want. Been doing that for years.