We used to troll a cutplug stick of non-salted butter on a triple hook set up with a toothpick in the front to hold it... Make sure to keep the the stick-o-butter on ice prior to fishing, the bait has it's best results in water temps around 50 degrees so the meltoff isn't too quick.

When they bite it, make sure to let them take it good. Once they get the mouthful of butter you don't want to set the hook too soon as the hooks could slip out of their mouth...

Killer bait, really.......

Keith