jigs?
From the post it looks like you mean plastic bodies. I would say its not worth your time to make plastic bodies when you can buy them for 2-5 cents each.
If you did want to make them you would need a mold. Some worm and grub molds are avail and you can have them custom made also. Most of the custom ones only mold maybe 2-4 bodies at a time. You can make a mold out of durhams watter putty, plaster of P, silicone, bondo...... then you need the plastic, and salt, and color, and heat stabilizer, and scent, and the actual plastic itself. Then you either have to heat it in the microwave in pyrex or get a like fry daddy pot and do a big batch at a time. If you had access to a machinest to make you a 20+ cavity molt that injected through one hole for all the baits(I have one I can show you if needed) then you could probably make enough and fast that it would not be too tedious. Yell if you want more info or direction. [email protected]
"Some days im Basstastic other days im crapptacular"