I use piano wire, which is sold on a coil. This coiled nature is certainly not conducive to nice, straight pushrods. Take a length of up to 24" of this wire, bend a 90° of about 1/2" on each end. Clamp one end in a bench vise. Clamp the other end in a drill, with the tag end sticking out of the drill chuck. Run the drill slowly, and I use the tag end to count revolutions. I put about 15 turns in per foot of wire, so 30 turns on a 24" length. When you've hit 30, put the drill in reverse for about 8-10 revolutions. This takes the pre-tension out of the wire that will whack you on the finger otherwise. I then proceed to turn the remainder of that original 90° bend into a Z bend.
This would probably work for coiled welding wire as well, though I've not tried it.