Greetings ezzy6.5,
Try a medium strength household Ammonia solution with water Cases into basket.Cover the top of ultrasonic cleaner well (it stinks) Switch on just experiment how long it takes to clean.Rinse in distilled or purified water.Dry gentle heat.You wont feel like fouling them again. If you are near B'Ham Tommy Suttons. Jewellers tools etc own brand Jewel Clean.will last you ages,Walsh in Beckenham,Kent will have their own brew.If you need to go down that route pm me
morena