Is there a safe way to de-ice an unsealed driveway?
Personally, I like to use sand. I keep a large barrel of it inside the garage door. Yes, it can be dragged inside the house on shoes, but then so can salt or anything else. When I come inside, I take off my shoes, so no problem there. I've used it under the tires of those people who occasionally get stuck on our road when it is icy.

Sand absolutely does not hurt plants, or the paws of your four legged friends, and it cleans up in the spring with a broom or a hose.

Sand is cheap too, especially if your town maintenance department lets you use their supply. (Make sure you don't use sand with rock salt mixed in already.) You can also buy what they call tube sand - coarse sand in a burlap bag. Its used around here typically as weight in the back of cars and pickups. When the bag gets old and starts to leak, I'll use that sand to spread on our driveway.