Mud snail cleaning shell. In the market to select the body of large shell thin, abdominal foot fat, no sand in the body, foot red mouth yellow, full of hidden meat, no broken shells of the mud snail, 2/5 will be salt according to the quality of the volume ratio of the brine made of 20% - 23%, soak the mud snail with brine in order to remove the mud, let stand for 3 hours - 4 hours, after that is the success of the de-shelling.