Pre-cleaning
While many dishwashers are very good at washing even moderate soil levels from dishes and silverware, if silverware is not getting completely clean, it may be because there is hard, dried-on or thick debris or soil on the utensils. Rinse silverware before placing it in the dishwasher, and remove any hard, baked-on or stubborn residue from the silverware.
Placement
When placing silverware in the dishwasher, point the heads of the silverware down so that the spray jets hit the heads first for more thorough cleaning. Do not overload the silverware basket as this will prohibit proper water flow. Do not mix actual silver with stainless steel as it may damage or stain the silver.
Rinse Aid Detergent
Rinse aid is an important part of cleaning silverware because it helps prevent water droplets from forming on silverware, which can cause spots. Instead, the surface tension of the water is lowered and the water merely flows off the silverware surfaces. Fill the rinse aid detergent dispenser regularly, or use a solid rinse aid unit that hangs down from the upper rack if there is no rinse aid dispenser.
Detergent
Using mild automatic dishwasher detergent should help keep silverware clean. Avoid using acidic, citrus-based cleaners as they may damage or leave spots on the utensils. Use the recommended amount of detergent each time.