It was a few years back (2008), but I did remember a "natural" deicer (doesn't solve all the problems) that seemed to work well & was a cost saver: salt water from rinsing whey: http://seattletimes.com/html/localnews/2008554980_roadsalt24m.html
but haven't heard anything since? -

Clarke O'Reilly (Biology Teaching)
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