You have adorable tiny frizzles!!
It actually doesn't take long - as long as you have a smart chicken. He worked with about 6 birds the first week - then narrowed it down to the top 2 for training. The fastest learner was a Serama named Popcorn. She learned to peck at the red target immediately and could distinguish colors by the end of her 1st or 2nd 5 min session. (Not the norm) However, she did not consistently peck at the piano keys hard enough to make sound. That's why the Modern Game was used in the video. The serama also learned that click = treat, so she would simply turn around and try to peck at the clicker to make us give her a treat. In general my son worked about 5-8 min at a time over the course of 3 months. He probably could have done it in a month or less if he did it daily. As with life, some weeks he practiced daily, other weeks only twice, and he crammed 2-3 training sessions per day right before the fair. LOL