Hygiene and cleaning.
You can do it with soapy water, but use just your hands or soft cloth. Dishwashing sponge will scratch the silver ot the gold plating. Rub with fingers some toothpaste to remove darkening on the flat silver surfaces but don’t do it with the patinated models. Silver itself is antiseptic.
They pass ultrasonic cleaning with disinfectant.
I don’t accept returns for them and I don’t resell them.