At a usucha (thin tea) party, people clean off the lip of a tea bowl with their fingers after finishing the tea, and then they take kaishi from the inside of the front flap of the kimono in order to wipe their fingers with it.
薄茶では、飲み終わった後に茶碗の飲み口を指でぬぐい、その指を懐の懐紙で清める。