Most camp showers require quarters - and I have run out of money in the middle of shampooing my hair. Children who normally take baths at home will not appreciate a camp shower. Many camp grounds do not offer bathing facilities at all. If you plan on camping for any length of time you will have to adapt. You can use them at home a few times to allow your children to become used to the idea.
Most kids just think of it as an interesting sprinkler.
Sponge baths can work quite well, especially if you are camping in cold weather. My son stubbornly refused to use the potty unless reminded every hour to do so. After he saw his father urinate on a tree a few times - all of our problems were over. He now stands up to potty and tells us when he needs to go. Camping trips are convenient for potty training.