I was just talking to my son about this very subject and though I have not used them he has. In Western Maryland he watched a man fish trout magnets with a noodle rod(a very long rod to 9 feet or more)the man used a small float that he could adjust the depth of the lure.He would drift the trout magnet through the current following the bait with the rod(like nymph fishing}bouncing the lure along the bottom.When the float stops lift the rod tip to set the hook,it can be very effective.You can also cast and jig them through the hole,with both techniques fluttering the rod tip ads action to the bait.

cast over the current keeping the tip of the rod in the air with a rapid jigging motion keeping the magnet close to the bottom white is my personal favorite I love live bait but a few streams down my way are lures only so I have grown to love them remember trout are a aggressive fish the more motion the better in clear water they may be a lil picky but stay out of their view and keep upstream from them continuously jigging in front of them will talk those trout right out of the water......compliments of team getting bent