2000 Nissan Frontier freon

That wasn't AC refrigerant. Both the older R-12 and the current R-134 vaporize almost instantly and will not leave any residue. The exception is if something on the car was damaged and some of the oil that circulates in the system sprayed out. If you can't wait for rain to slowly wash that off, clean it like any other grease. You can use dish soap, bug and tar remover, or a product called "Super Clean" from the Chrysler dealership. Other manufacturers and auto parts stores will have the same product with their own names on the can.

Liquid refrigerant is extremely dangerous to work with. It can cause blindness and frostbite. If someone really did manage to release some of that, you can see why professionals wear gloves, safety glasses, and a face shield.