I know your set on getting one of these clips but I reckon your better off just leaving the reel in gear. In my experience if a King is going to eat a bait it will do it with the reel in gear and get hooked no problem.
With the bail open on a spin reel it will still feel some resistance, not to mention the resistance from the line in the water. The fish will have time to drop the bait and not hook on.
When the reel is in gear the King has no time to think when it grabs the bait. As soon as it grabs it, it moves away and it hooks on.
Just my opinion.