First, rust must be removed, and rust removal paste should be used.
Second, if the corrosion is not deep, the rust remover is unlikely to affect the false blades.
Thirdly, if the rust is deep, the false edge is also removed after rust removal. There are two solutions. One is to simply grind off all the fake blades and polish them by hand. At this time, you need to buy grinding cream; One is to stick adhesive tape on the blade, cut off the fake blade with a knife, and then polish it with coarse sandpaper to make the fake blade again.
Fourthly, I personally recommend putting this cos knife aside and spending 100 yuan to buy a knife that is at least made according to the real specifications. Although the steel mouth is not good, because it is not the "screwdriver" of cos knife, it is safe to play and feels better.