Welcome unclefish!
Do It has had 3 versions of an Arky jig. An older one has a fairly short ball collar, so not really made for plastics. The other has a ring & barb, and then there's the Trokar version. I have all three and have added single wire keepers to two of them. Actually I have 4, as one mold type, is also made in two versions, for two different hooks, an inline eye and a cross eye.
It's as simple as placing a hook in the mold and a wire keeper where you want it, and gently closing the mold to keep it in place. Then using a bench vise, or large c clamp, close it shut. I use two pieces of 2X4 on the sides of the molds to distribute the pressure evenly. The same can be done with two wire forms or you can probably tape them in place using cellophane tape ( scotch tape) since it's very thin.
You will need to use a hook in the mold, otherwise the wires will move.
I'll sometimes touch up the impressed slot with a Dremel & the smallest cutter they make if it's got too much flash. I generally use the WB800 wires in everything, and it's larger than the WB400. I'm not sure how this might work if you try the WB1000 that has two hooks, I've never tried it. That would be easier for pouring if you can get it to work, since it's one wire form, but it may be hard to get it centered because of how it's made. Using two of the other wires, top & bottom on the collar would be easier to do for making the impressions. However, since that mold does have a lead barb, not sure you would need two wires. I added the wire to the bottom of mine since the lead barb is on the top side. It works great holding plastic trailers.
I really like the Trokar Arky head, but have never tried skipping it. As Efishnc mentioned, you can use other 60 degree bend heavy wire jig hooks in it as well. I've used Mustad, VMC, Gamakatsu, Owner & Daiichi in mine.