Berkley Gulp Sandeel - what is it ?

Hi

I read an article recently in which the writer stated that the Berkley Gulp Sandeel was "excellent for estuary fishing and spinning off the rocks......... " I thought I would have a go at them and they arrived this morning, but I'm confused.

From looking at the packet they are obviously used as substitute bottom bait as they come with a 'flavour'/'scent' and are contained within juice in the packet. Are these the same thing that I read about and can they simply be used for spinning also as suggested ???