Got the idea from a Thai lure maker. Here's the video to that lure: https://www.youtube.com/watch?v=yuuPNS7MWBQ
Swim action is in the third half of the video (ref: Car Talk). There's an air chamber near the head of the lure. You can add a steel ball in there for a rattle or you can add it in the belly weight cavity. It's a one piece lure so you have to add it half way thru the print; set your alarm. The thru-wire hole size is .100" and I use the .041" lock wire from Harbor Freight. It comes in a blue plastic cylinder. https://www.harborfreight.com/0041-inch-stainless-steel-lock-wire-1-lb-coil-8895.html
Update: added belly hook hole.
BellyhookSnakeHead_w_eye_sockets.STL | 704.1KB |