I originally tried out the Orange scented (not Grapefruit) Citrus Air Freshener, and loved it. It's been around for years, and I bought it because it uses natural oils over harmful ingredients. When I saw the Grapefruit scent, I had to try it..and now I keep both in my home for some variety.
It is very easy to use, and you really don't need much. I live with someone who smokes occasionally, and when she leaves, all I need to do is spray one or two pumps, and I can no longer smell the tobacco! Other products I've used either (quite obviously) cover up other scents, or leave me with a headache because...