It works. I NEVER chase a chicken...there's just no need for it and I'm too fat and old to even try.

Keep a nice, bright light over a work station in or near your coop for bird exams...you'll be thanking yourself for it as you go along in your flock tending life. If you have to examine a bird's vent area, just grasp the feet and lay it gently on its back on your work station, lift the feet towards the head and use the other hand to part the fluffy feathers.
I don't handle my birds overly much, but twice a year or so I find it necessary, either to examine their skin for any evidence of parasites or to examine them/tag/measure them in preparation for culling. All of this is done at night where they can calmly be collected off the roosts, examined under a bright light and returned just as calmly.
It works best if you leave the roost area as dark as possible and place your light at the other end of your coop or even outside your coop....full light on the roosts will make them more restless and more apt to jump down off the roosts while you are trying to select one for handling.