The black film on the tripe does not need to be washed off. Because the black film is part of the body of the tripe, tripe itself is black, so this black film is edible, do not need to deal with. Just wash away the mucus or impurity dust on the surface of the tripe.

Use salt to rub the maw inside and outside repeatedly, can remove most of the mucus and dirt.

Rub the tripe with vinegar to remove most of the odor.

Put the tripe into a bowl, add 10 grams of yellow vinegar, 1 gram of salt and mix well, and rub hard to remove the fishy flavor.