1) When you pour hot water on them, don't be surprised if you destroy your panels.
2) You don't need to clean the snow off the panels perfectly anyhow. Go to your local big hardware store and buy an extension pole.. long fiberglass pole painters and window cleaners use. The one I have goes from 9 feet to 16 feet. Put a push broom at the end of it and use it to brush the snow off the panels by starting at the top and pulling the broom down..
There is no need to clean the snow off really well because the dark solar panels will quickly heat up as they are exposed to the sun.. and once that process starts, it accelerates quickly.
The trick is to try not to leave any 4 inch thick clumps on the panels.. but even then, when they heat up, the layer below the clump of snow melts and the stuff usually slides right off on its own. Of course, this depends on the angle of the array.
Hot water is a very VERY bad idea...