Select a plastic pail with a snap-on or screw-on lid, such as an old paint or food container. Remove the lid and clean out the pail with a rag.
Place the lid upside-down on top of a flat piece of scrap lumber. Drill about 12 holes through the lid, spaced evenly apart, using an electric drill with a 1/4-inch bit.
Hold a metal drawer handle against one side of the pail, as close to the center as possible. Drive in two galvanized metal screws, through the holes in the handle and the plastic wall of the pail, to hold the handle to the pail firmly.
Fill the pail with rock salt by scooping the salt out of a larger pail or plastic bag just before using it. Attach the lid firmly before use to avoid spills.
Rinse out the spreader after every few uses to prevent residue that can damage the plastic and metal components.