In general, machine washing is the worst way to clean silk, as the agitator and other garments can damage the fabric. However, if the instructions for your washing machine state that the machine is safe for silk, there should be no serious problem washing your luxury silk bedding duvet set in it. Before washing, make sure there’s no soap or dirt on the inside of the machine that might stain the silk item. Place the silk item in a mesh bag or a pillowcase loosely tied closed. Use a small amount of a very mild appropriate detergent and wash on a gentle cycle, such as a wool cycle, at a temperature of no more than 86°F / 30°C. If you use a spin cycle, keep it as short as possible.
Be careful with every step when you are determined to machine wash your luxury silk sheets! Since you have invested so much money, don’t be mean on energy!