I had an idea today after talking to a rather grizzled looking, rollup somking rod and reel fisherman, when i was walking along Filey bay. Now Filey bay is very boring for fishing/spearfishing due to its flat and featureless sand bottom but what he was doing was soaking a 1" cube of sponge in a fish oil and tying it just above the hook to draw in the fish (the oil is made made by boiling fish bones, skins and heads then skiming the oil/fat off the top). now my idea is verry similar but sutf a sponge into a 500ml bottle (the top half dotted with holes) pore in some of this fish oil to saturate the sponge and hang it from your buoy to atract the fish into you. Can anybody see any problems or can offer any improvements please let me know.