Yes, hatchery hybrids like CXs, Hubbards, ISAs, Shavers, etc. are not considered breeds, and don't hardly do well in shows up here in Canada, all the less down in America! Most people prefer to use true Breeds for showing, although if you have good looking hybrids, they should be showable.
Before showing a bird, I'd suggest the following:
1. Go to a Show and see how things are done.
2. Get a copy of the Standard for the breed you are showing to see what that breed should look like.
3. Check out a library book or look online for what is done to prep a bird for the show.
4. Check with the Show secretary (back to #1) concerning any testing that must be done prior to arriving at a Show.