I recently bought some Gunk'* Engine Brite in hopes of cleaning up my engine. Reading the other posts though it sounds pretty bad if you get some of the electrical parts wet. What parts do I need to make sure are covered before I start spraying this stuff on and where are these parts located? Should I spray on the undersides of the engine as well (ground up)? Also, can I spray this stuff on everything else without worrying about it eating through anything important (plastic, aluminum, etc)?