I've left a bar of Ivory soap in the shower stall with the water left
dribbling and what's left is not shaped like a bar of soap anymore, more
like the skeleton of a bar, with crevices.

This happened before several years ago.

Has anyone ever seen this?

Is there a term for this so I can google. I've tried remains but that
just gives advice on how to take slivers of soap and put them together
to be big enough to use. I've tried skeleton.

With Ivory soap or some other brand (Ivory is different because it's
mixed with air, though I don't see how that would make the difference
here.)