a question about shell fish such as clams

[Dr. Dan]

i had an interesting discussion the other day about this.

If the shell of a mollusk were completely cleaned from the mollask that lived with in it, can it be used as a tray to serve, let's say, vegetables, kosher cavier etc?

I was told that if it was cleaned properly, yes.

If this is true, then is it wrong to eat from a cleaned ceramic plate that served trayf foods?