Fair Superintendent here!
Wanting to share some good advice about prepping your 'kids' (both avian and human) for your county or state fairs.
First off, make sure that your guys and gals are healthy. Do a thorough health and parasite check. A lot of the times, 90% of the parasites I see come to fairs via birds are leg mites, or scale mites. This can generally be cleared up with Vasaline on the legs for two weeks strait a month or more before the fair. Apply in a thick coat with a toothbrush and brush backwards up into the scales. I have heard that a lot of people have used mineral oil. The only problem with this is the oil isn't thick enough to coat the scales for an extended period of time, which is needed to suffocate the mites. Either might create some dirty looking feathers so you may or may not have to bathe a bird.
If you have other parasites, such as feather mites, you can use any of various products to dust your birds with. I don't dip mine, never have, never will. I, honestly, have only dusted one bird in my entire life, so instead, choose diatom. earth. I know there is a big movement right now to not use it because it can get into the birds eyes and make them blind. From experience, having used it for 20+ years, I have never had a problem. Plus this will also take care of internal parasites as well. If you put a little bit in their favorite dust holes you will be just fine.
Second, make sure you have all the necessary equipment. Most fairs have housing cages for the duration of the show, if so-great, if not, bring your own. If they do, take a spray bottle full of either peroxide water mix or vinegar water mix and spray down your entire cage BEFORE you put any of your own equipment or bird in, this will kill anything that may have hung around from last year or anytime in between. I know a lot of fairs and shows will offer feed and water equipment but you are always free to bring your own. On the water note, sometimes switching to a different water supple than your own will shock the birds, especially if you are going from well water to chlorine. A simple fix would to 1) either bring your own water for the duration of the show or 2) put about a tablespoon of baking soda into a gallon of affected water and then give to birds. This acts as a neutralizer and will cancel out the effects of the chlorine and make the water taste 'normal' to the birds.
Third, when at the show or fair, make sure that you are taking care of not only yourself but all your birds. I know it can get very hot at some of these show so here are a few good ways to keep your birds cool:
-wet rags or towels with fans blowing through them
-frozen jugs of water, either gatorade bottles or pop bottles filled 3/4 full then frozen solid.
-frozen rubber mats. There is are few brands of rabbit mats that are rubber and designed to be frozen and then the rabbits can cool off from underneath. These work really well for birds! When they get messy, you can just spray them off with water and refreeze.
Make sure that you as an exhibitor or showman are drinking plenty of water, staying cool, learning lots and having fun!
Good luck this season ya'll!