You actually do need to wash the outside of melons. When you slice a melon, the knife passes material from the skin area onto the cut surface, which goes into your mouth.
Havanesemom, I would send some info back to corporate asking them to change their practices. Gross.
I happen to agree with Peter on this one. But I think the worry has nothing to do with gluten. That stretches into the realm of unreasonable worry. I do not wash produce because I am paranoid that it has gluten smeared all over the surface but because of bacteria and germs. There are people out there who I wouldn't let touch the door handle on my car, let alone the food I eat. Many people have handled melons on their route to the food store and it makes sense to wash them before cutting from a germy viewpoint only. But if you think you can take a gluten hit from unwashed melons.........put the order in for the plastic bubble soon!