1, salt has the function of disinfection. When washing the cup, you can add a small amount of salt, hold the straw with your fingers and rotate it. After washing with water, the dirt will flow away with the salt, thus achieving the cleaning effect.

2, you can use a slightly larger hairpin, choose a wool with a thickness about the size of a straw, pass through it from one side, and then pull the wool back and forth, so that the dirt in the straw can be removed.