Tom
I think you sell a sharpener that works on the neckers? The sharpener with both a straight and sissor carbon tool? To sharpen the neck use the part of the tool made for doing sissors.
Trick with the necker is to never touch the back edge of the blade and just sharpen from the one side that is up when cutting. If I go on the back of my knife at all it's maybe one past to knock a burr down. Most time I just use a couple swipes with a steel, I don't believe I have use a stone.
Mac