Mine did that on the road the other day actually - it's a bit scary isn't it. If only the gritter lorry could fit down cable outers, eh?
If we had winters like this for a bit longer (who knows - we may do) then maybe some diesel on the cable itself might work. I really wouldn't know though, and you'd probably wreck your cables.
Doesn't the snow slow you down enough anyway?? Why all this obsession with stopping on this site? ;-)
when i have raced in the snow and ice beofre i have used deicer sprayed all over chain chainset brakes to try and stop this and to stop all that slushy stuff attatching itself and clogging everything up