Rock Salt can help snow settling but is better used after snow has been cleared to prevent paths, roads, driveways and steps icing over. It works by creating brine which is a solution of water and salt. This has a lower freezing point than ordinary water and by putting rock salt on ice will cause it to melt. A small amount of salt will weaken the ice allowing it to be easily removed by other means.
Rock salt can be damaging to plant life. It can also leave a messy residue.