Our front porch and steps are concrete so when they get ice on them it's impossible to to spread salt to melt the ice because of the damage it does to the concrete.
An easy and effective way, also cheap(!) is to make my own ice melting compound. First, I bought a 32 ounce (¼ of a gallon) Zep brand plastic spray bottle at Home Depot for less than $4.00. This spray bottle is great...it will squirt liquids 6-8 feet. Now that I think of it though, I should probably invest in a 2 gallon plastic watering can for about $5.00.
Put 1 teaspoon of Dawn dish washing liquid and two teaspoons of rubbing alcohol into the bottle and filled it with warm water. The original instructions said use a half gallon of water, but I didn't have a bottle that big.
One site I was on said this would not work, but it did. However, I have no idea as to how low the temperature has to be for it not to work, nor do I know how long the ice will stay slushy. I suspect it would be perfect for use where steps and walks are covered with freezing rain.
Of course, calcium chloride pellets are best because they are hygroscopic, meaning they draw moisture form the air and ice, which enables it to work when other deicers cannot. No other ice melter out performs calcium chloride pellets. It melts ice and snow down to temperatures of -25 degrees F. and it is safe to use on concrete and vegetation when used correctly. But it is expensive.