Two part question. Is there a timeframe swimjigs are more effective for y'all?
And I usually use a santone Rayburn swimjig with a swimsenko as a trailer. I ordered the siwash swimjig and they have the screwlock keeper. How do you properly thread a trailer on there without destroying it?

I'm not sure if I'm understanding you because if it's a screw lock keeper, your trailer should just screw onto that with ease...? Maybe I'm not getting what you're asking though.

There is a screw on the shank of the hook

Thread the bait onto the hook just like any other keeper hook. After you pop the point out of the plastic and as you push it forward start rotating the bait when it touches the screw lock. You will have to tuck the tail of the trailer under/around the point/barb of the hook on each rotation. Make sure you don't let the bait press against the barb or it will slice the plastic. It is really quite easy when you get the hang of it.

Ah...gotcha.