Ashes, unfortunately, don't have any particularly stellar effects on snow. Ash can assist with traction, but it offers no ice melting properties. Cat litter, basically a clay-based product, offers similarly unimpressive results. Much as trash doesn't belong in plants and water systems, heaps of ashes and cat litter may negatively affect your vegetation and run into waterways. So the issue of properly disposing of the leftover muck needs consideration.
Sand is a commonly used easy-access option.
Henry Kirchner is a Professional Engineer registered in Michigan with 18 years experience in de-icers and winter maintenance. Now a consultant for companies and the legal profession, he explains that environmental and social consequences exist from using sand. These include the clogging of sewer systems, greater potential of corrosion to vehicles from hard-hitting sand pebbles that scratch the auto's finish, and increased risk of scratched or chipped windshields from the motion of cars that cause the sand to act as sandblasters. Kirchner and Bruce Juelfs, streets supervisor for the city of Fort Collins, Colorado, share similar concerns about the impact of sand. Of special concern to both is the deterioration of air quality that occurs in areas where sand is heavily used.