Not trying to convince you just would liket to point out swivels are primarily used to prevent line twist. Any fish that has the ability to INHALE a 400 gram rip roller has the ability to twist the shit out of your line during an epic battle. Not to mention most jigs are designed to roll, flutter etc which will also contribute to such. My 130 JB spectra cost me $200 I prefer to keep it untwistedOn my last trip, 2.5 day 5/13-16, I toured the rod racks, port and starboard, checking out the different rigging methods used for the knife jigs we all had rigged up. I swear, no two anglers used the same method. Personal preference is what I saw and most of them looked like they would work. Most used a swivel somewhere, top of the leader and/or bottom of the leader.
Again, not convinced that swivels are needed.