Put live clams in water with a little edible alkali, soak for half an hour, then take them out and put them in clean water. Repeat this for three times, and basically all the sediment in the clam can be removed.

The principle of this practice is like gastric lavage. Because Meretrix meretrix is an aquatic mollusk, it needs to moisten the respiratory organs by spitting out the water in its body after it comes out of the water. So it consumes a lot of water in the body after it comes out of the water, and then it will drink a lot of water immediately after it is put into the water. Adding alkaline noodles to water will make it feel uncomfortable, just like vomiting. After adding clear water, Meretrix meretrix will immediately spit out the alkaline water in the body and inhale the clear water, thus bringing out the sediment in the body.

The method can be used for cleaning other fresh shellfish, live fish, live shrimp, live crab, loach and other aquatic animals.

In addition, concentrated brine can also be used instead of alkaline water, but the use of alkaline water has the advantages that saline water does not have, that is, it can also remove protective mucus from the surface of living objects.

PS: I found this from the Internet. Generally speaking, we just put it in salt water. As for excrement and sand, you have to keep it for half a day to one day (depending on the situation) before you can discharge it.