Ruling on using sea-shells to clean oneself after defecating

We put this question to Shaykh Muhammad ibn
‘Uthaymeen, who replied:

No, rather it is permissible to use them because of the hadeeth,
“For you is every bone over which the name of Allaah was pronounced [when the animal
was slaughtered].” And these shells are not slaughtered, so they are not like animals
which we are permitted to eat, over which the name of Allaah is pronounced at the time of
slaughter, and the bones of which we are forbidden to use to clean ourselves after
defecating, because they are the food of the Muslim jinn, as stated in the hadeeth quoted
above.

And Allaah knows best.