I used these at a restaurant for about four months, filling them with soy sauce. They're very well-designed and don't drip. I washed them every other day, so I don't think there are any soy sauce smells or stains, but please refrain from purchasing if you are looking for perfection! I have 15 of them, and I'd appreciate it if you could buy them in bulk (^^) I'm not opposed to selling them individually, so please feel free to ask! They are sold out on the Miyama Dish Shop online store, so don't miss this opportunity! Regular price: 2640 yen miyama japan