I can't think of any wax that will survive the heat. I would just clean it and polish it.
If you really wanted it looking like new you can probably polish it with a buffer. If it was left in the sun it will take the oxidation right off. If it's just hazy, a normal chemical deoxidizer should work.
If there's sap and stuff that normal cleaning cant remove, try a clay bar from the automotive aisle. It takes stuff off that's stuck to the surface quite nicely without a buffer and much effort. Good luck!
Corey, take some white vinegar in a spray bottle, spritz the kettle all over, let the vinegar set for a moment to loosen the grease or whatever, then wipe clean with a damp cloth.