Fill a bucket with about 2 cups of wood ashes. Pour in a gallon of water and stir well. Allow the mixture to sit overnight.
Strain off the floating bits of charcoal and wood matter with a sieve, taking care not to disturb the liquid.
Pour the liquid into another clean bucket, stopping before any of the sediment at the bottom drains into the bucket. The fluid contains the dissolved potassium and sodium salts.
Add an equal amount of plain white vinegar to the bucket and mix. This acid will react with the potassium and sodium forming a weak potassium acetate and sodium acetate. Airlines use potassium acetate to de-ice their runways and planes.
Pour the liquid into your garden sprayer and spray over your driveway and walkways before the snow starts. The lowered melting point of the spray solution should keep ice from solidifying or snow from accumulating.