The kit that Moe's sells works very well. It's a very popular method of trolling for salmon in the PNW.
Close.Use the spreader only in very hard current like Buoy 10 area. It does allow you yo turn sharper e/out messing up the line. Also, use a flourocarbon leader tied from barrel swivel/chain from spreader to lure.
P.B. May 2009 Columbia River, just west of Camas, Washington 9ft. 4"