I use One-Shot Sonic Cleaning Solution for cartridge cases. A few drops is all that is needed. Wet tumble for 1.5 hrs and inside and out is super clean. Using Dawn would take 2 - 2.5 hrs.
After separating brass from the pins and rinsing the brass, I use an air compressor to blow off the extra water, then lay out on a bath towel. All dry in a couple hrs.