The most effective fish mouthwash is dopa salt, which is a kind of fish hunger hormone, which can stimulate the taste buds of fish and transmit them to the central nervous system of fish through the afferent nerves of fish, making fish feel hungry strongly.

Doba salt has a strong feeding promoting effect on freshwater fish, and it is non-toxic, especially on freshwater fish such as carp, crucian carp, herring and grass carp.