For brass
My cleaning solution mixes 2 tablespoons of anhydrous (powdered) citric acid in 1 gallon of tap water, with a splash of dishwashing detergent (such as Dawn).
1. Fill the ultrasonic cleaner tank with tap water, to 1" below the maximum fill line.
2. Fill a 600ml Pyrex or Kimax laboratory beaker about half-way with cleaning solution.
3. Place the beaker in the tank and allow the cleaning solution to go through 3 or 4 8-minute cycles. This will remove the bubbles from the solution and enhance its cleaning ability.
4. Place 25-30 de-primed cases in the beaker and run for 3 8-minute cycles.
5. 1 8-minute bath using hot tap water.
6. 1 8-minute bath using distilled water.
7. Place cases (mouth up) in a loading block and permit to dry (air dry or hair blow dryer).
Works great for me.