:-D Greetings from the Great White North:
I have a friend who swears by the powdered soap you use in an automatic dishwasher. He boils the water in a kettle. Puts the water in the sink. Adds a couple of heaping table spoons of soap and swishes the cases around. He rinses them off and leaves them to dry. No streaks, no marks.
If all else fails, try using a can of break degreaser. If it's good enough to get the gunk off the breaks of your car, it'll get the gunk off your bullets and brass.
Kindest regards,