I use both splitties and pencil lead, you will only need a small piece, 2-3 " and concentrate on the float being staright up and down, avoid holding back on the float or your jig will just be a colored little stick and not the pulsating lively attractor that slays fish.
Coho like blues, Olives, brown and Orange, which can be hard to find at the stores, so maybe tying your own will serve better.
Get some GOOD hooks, jigs need good hooks and many comercial jigs still come sporting walleye hooks.
Have fun and your right, presenting something different is a big piece of the puzzle in busy rivers like the Chedder.