I have 4 8 week old pullets. 2 Barred Rocks and 2 Red Sex Links. One Barred Rock has started pecking. Well, I just watch what they do to each other and did what they do. If a chick pecks you softly, like it is just curious, I don't care. If it pecks your hand or leg pretty hard, I call out with a loud BRRR! Like they do when they jump on each other. It really works! So far, I never have to touch them to correct them. Like horses they really sense our energy more than our wanting to use physical force.
Just for fun, try it. I hope it helps!
All the best