It doesn't take anything special to scrape the heavy grease from a hood, go to your local hone center, and get a variety of scrapers probably from the paint section. I would get a wide one, 3 inches or so, a narrow one for tighter spaces. You may want to get a razor scraper for really tough jobs. I use a wall paper scraper, "blades are replaceable” and finally get something you can attach to a pole for hard to reach area's and to reach into ducts.
You may also discover that the perfect scraper doesn't exits, you will always get into something where the right tool just doesn't seem to be available. The ability to adjust on the fly or even invent something may come in handy can anyone say Magyver I think I spelled that correctly