I have done the picking up and walking or holding a rooster and it has worked for me and my boys. I have also put them individually in solitary (large dog kennel) where he can see the hens free and enjoying the day, but he is far off and watching. For me these have worked 100%.
I edit to add that I ONLY do this during the immature/young teen stage before they have spurs. My degree of injury is low and it is better for him to learn right now that I will not spar with him and that the option is not even there. He also might as well learn these things before he has them set in his mind when he is mature. Have had to do this with 2 out of 4 roosters and waa-la no more aggressive roosters. They run to me and eat out of my hand. I will add that I do spend time with the entire flock just hanging out, cleaning the coop, hunting for eggs, and just stuffing them with treats.
I edit to add that I ONLY do this during the immature/young teen stage before they have spurs. My degree of injury is low and it is better for him to learn right now that I will not spar with him and that the option is not even there. He also might as well learn these things before he has them set in his mind when he is mature. Have had to do this with 2 out of 4 roosters and waa-la no more aggressive roosters. They run to me and eat out of my hand. I will add that I do spend time with the entire flock just hanging out, cleaning the coop, hunting for eggs, and just stuffing them with treats.