Thick lip mullets love oil?

[Tjockläppad Multe]

I remember reading that english fishermen use to feed mullets fish-oil to get them feeding. I've also heard loose rumors about mullet fishermen who poured "cooking oil" in to the water to attract mullet, with good results. Fish liver oil is ofcourse quite hard and very expencive to buy. But I'm thinking about maybe squease some shrimp heads or herrings in to some regular corn oil and use this as groundbait together with bread to get mullets feeding of the surface in harbours and such.
Have any of you guys had any success with this, or even heard about this before? Will I just look like a fool pouring expensive cooking oil in the water?

[KKK]

Cooking oil in a 25lb onion sack of bread mackerel and most other bits you can find put it all in the sack as ruber Dubby and it does attrack mullet as do chicken bones in the sack.