I talked to him last night. It is not higher octane fuel, but the E85 fuel that you can run two tanks through before you change them. That fuel somehow causes the engine to burn hotter in the cylinders and burn off any carbon build up that might lock the spark plug in place and cause you to break it off. It seems to be a common issue with that engine. He did break one spark plug during his replacement, but doing the work himself saved him hundreds of dollars. I may put my car on the ramps this weekend to see where everything is under and over the engine so that I will have an idea of where the spark plugs and oil filter are located. If nothing else, I will at least become more familiar with the car.
People also use a product called SeaFoam to rid of carbon build up and other gunk and built up stuff in the engine.
Seafoam would be a good option IMO.