Method 1: firstly, wash the outer wall of the small intestine, then turn the small intestine over with chopsticks, with the inner wall facing outwards (when turning, separate the ones that have not been turned over from the ones that have been turned over, otherwise the dirty things will stick to the outer wall), then put in large grains of salt, sweet potato powder and vinegar (the large grains of salt can be used as sand), and then repeatedly rub and wash them, when the mucilage on the inner wall of the small intestine is all large grains. After taking it out, add some surface alkali, that is, edible alkali, and then rub it again, and then wash it with warm water for several times to take it out, and you're done. After these two times of feeding and scrubbing, it is guaranteed that there is no odor at all.

Method 2: Or wash the outer wall of the small intestine, turn the small intestine over with chopsticks, turn the inner wall outward, pour some cooking oil, and rub it repeatedly. When the sticky substance on the inner wall of the small intestine will fall off by itself, then pour clean water, and the water drops will dry. Then add salt, pour a spoonful of vinegar and a spoonful of wine (our common cooking wine) and rub it repeatedly. Rub it evenly and wash it with clean water. Pick it up, dry it, put it in a basin, boil a pot of boiling water, soak the small intestine in boiling water for 2-3 minutes, then pick it up and wash it. That's enough.

Method 3: Put the bought pig small intestine in the refrigerator first, and then take it out to remove large visible oil. Put a chopstick against one end of the pig's small intestine, then put the pig's small intestine on the chopstick until the other end passes through the chopsticks, turn the small intestine over, and then wash the turned pig's small intestine with warm water first and take it out. Add a tablespoon of sweet potato powder (or flour), a proper amount of vinegar, and a tablespoon of salt, fully knead with your hands, and then rinse with warm water, so that the dirt and mucus on the small intestine can be removed very cleanly.

PS: Don't think that it is difficult to clean the pig's small intestine. If you can master some scientific methods, you can clean it quickly.