To clear up a few points.
Both Alcohol and antifreeze and deicing solutions ( as well as salt, and
almost any other substance that dissolves in water ) lower the freezing
point of water. So both alcohol and antifreeze both effectively melt the ice
by lowering the freezing point to below the current temperature. Since the
sprayed solution only contacts the top layer of the ice, it melts it away in
layers. The idea that one only melts and the other only prevents refreezing
is an OWT. Using a heated substance will melt it faster because you
simultaneously raise the temperature and lower the freezing point.

Some mentioned that spraying hot water only on the plane is prone to
refreezing in a dangerous way. Sage advice.