I tried using a big weed-burner propane torch to melt ice on the sidewalk once. I ended up with nearly as much ice that night when the temp fell. I guess there wasn't enough evaporation.

I didn't try that again.

I'd expect that adding water would make the situation even worse.

Others may have different experiences.

Rock salt works for me. :)

"Rock salt works for me."

And also tends to kill any plant it gets near (soaks into the root zone).

Epsom salt, Calcium chloride, urea and a number of other ice/snow melts are easier on your plants.

On brick steps (or expansive stone work) even denatured alcohol works well (at a sometimes painful price, but often less than repair).

Even if the air temperature is above freezing, chances are the temperature of the driveway itself would be low enough to freeze the additional water, and if you have any low spots that would puddle, those would most likely become mini ice skating rinks. I would think there would also be the issue of runoff, that water would need to flow somewhere, and I wouldn't want to be responsible for causing a frozen pond in front of someone else's home. And my last concern would be from a purely environmental standpoint....the amount of hot water that would be necessary to be sprayed onto a driveway and/or sidewalk in order to melt off ice and snow and the energy that had been consumed in creating that hot water.

This year, I did not put a heater on my fishpond, and lo and behold, I had several inches of ice (perhaps 6 inches). My daughter and I were determined to put a hole in that ice so the fish didn't die, and it took WAY more hot water than I imagined it would to create a hole. I found that the hot water immediately cooled down to the point of being useless almost as soon as we poured it onto the ice. We finally were able to make a hole through the ice, but it certainly was not an efficient way to go about doing it.

My suggestion would be to hire a service to clear away the snow, if you are unable to do it yourself, and use one of the "ice melt" products available...or kitty litter if you prefer to not use the chemicals. Kitty litter is messy, but it won't deteriorate your concrete, nor damage your plants. It also won't melt the ice, but it will provide traction.

It takes a lot of energy to turn ice at 32F into water at 32F due to something called latent heat. I suspect that you would run out of hot water long before you made a huge dent in the ice in your driveway. And what you did melt would probably re-freeze, and then be even more slippery. In short, a potentially expensive way to turn this into a bigger problem.