I think if you concentrated on the aerodynamics, or hydrodynamics, of the lure, this would be the easiest solution to implement. If the lure was rear weighted and the design of the lure was such, that it would want to "swim" backwards, you could possibly get what you are looking for. I think the biggest problem with this design, or any design for that matter, would be your 100% energy return. Just like an unpowered pendulum will never swing back to it's original position, the lure will not want to, either. It looks like this is why you were trying the spring loading idea.
-Chris
1 acre pond
Currently managing:
FHM, GSH, GSF, BG, PS, RES, LES, YP, SMB, LMB, HSB, RBT, WE, CC, FHC, and Grass Shrimp