Bleach is used for the outside of the shell, not for the animal.  If you don't get all of the animal out, soak it for a day or two in fresh water then put it in Hydrogen peroxide and that will
eat the animal out.  Don't use it on glossy shells.  I do it with very tiny shells also.  It eats the animal out.  I watched through a micoscope while it ate the animals out of some Caecum and
the Caecum were still very shiny.  It works well on terebras.  If the terebra are starting to decay it works much better.  That's my two cents.

Bob

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