It helps to select a calm chicken or one that is used to you. When they are comfortable with you they will do anything you ask them to do. A well behaved chicken can make all the difference when training. Food is often all you need. Clicker training works well, but treat training without the clicker works well too. I've found that if the food simply appears instead of being associated with a hand it works better. This way the bird is not always looking at you for food or waiting for a clicker sound. They learn what is expected of them very quickly, especially if you involve food.
Chickens are very smart and easy to train. they often learn without the aid of food or a clicker, but those things do help the process along.
I've found that bathing a chicken one or two days before the show works best. Be sure that the bird has enough time to dry out all the way.
When bathing a chicken Dawn Dish detergent works well. For white birds I've found that a mixture of Ivory Soap and Bluing will make those birds shine. Be sure you dilute the bluing first or you'll end up with a purple chicken. You can also use any non medicated pet shampoo as well.
Chickens be bathed in many ways. My preffered method is to use the bathtub or the kitchen sink. You can also bath your birds outside with a bucket of nice warm water. When you have running water hold the bird firmly and wet it under the water. Be careful not to soak the bird's head, they don't generall hold their breath when submerged. Once the bird is wet apply a small ammount of soap to all parts of the body and work it into a lather. Rinse your chicken thoroughly and be careful not to get any soap in their eyes. Keep washing until your bird is clean. If your chicken is really dirty you may need to wash and rinse several times to get them clean completely.
You will need to dry your chicken off to keep it from getting to cold. Dry the chicken thoroughly with a towel. don't be afraid to really rub the feathers down. It sometimes helps to grab handfuls of feathers and gently squeze the water out of them. Run you hands across the feathers to fluff the chicken up a bit before you blow them dry. Use the warm or cold setting and not the hot setting of the dryer for your chicken. You can use a regular blow dryer to dry your chicken. Be careful not to overheat the chicken while you dry them. Don't worry about ruffling the feathers, your bird will preen them back into place.
Once your chicken is clean and dry place them in a clean cage with a nice bed of shavings or a good wire floor to keep them clean. Don't just turn them loose in the coop with the other chickens who might get it dirty again.
Bathing your chicken will make it's feathers nice and soft and it will shine. even regular dish soap makes a big difference. You can always tell the birds that were bathed and made ready for the show and the birds thet weren't. Taking this extra time will make you stand out from the group.
The day of the show be sure to do a bit of a touch up on your chicken. Apply a bit of mineral oil, baby oil often leaves a residue, to the feet, comb, and wattles. Check the feet for any poo and wipe them with a baby wipe before the oil is applied. clean any last minute smudges off the feathers and be sure to check those foot feathers on feather footed birds. Your bird is mainly judged on cleanliness when you are in showmanship.
Don't forget to smile and have fun while you are showing. Be calm and your bird will be calm. Talk loudly and confidently. Own your answer. Stand up straight, but not stiffly or overly serious. Look calm and confident. Judges often like to see kids enjoying themselves instead of looking overly serious or nervous. Always make eye contact and watch the judge not the person next to you or your parents.
Always handle your bird gently and never get angry at it. Move slowly and be precise. Know what you are doing, or at least act like you do.
If you don't know the answer it is better to say you aren't sure than to give a wrong answer.
Most importantly just have fun and learn! That is what 4-H is all about!