For years outrigger clips were dead simple, (same idea as downriggers ) and are still used on many, many game boats today.
The line from your downrigger to weight attach a link swivel at whatever position you decide on can even add a length of mono, wire whatever but not needed if the weight has stabalising vanes to stop twisting. Between the main line and downrigger line, a simple elastic band, job done.
Size of band depends on what you are towing lure wise but that is a simple bit of experimenting. When the fish hits, elastic band snaps, fish on main line (you hope), sorted.
You can even make your own downrigger weights with pea or bean cans, (small kiddie size).