I have read on a council website or two (whilst googleing salt suppliers), that it is highly unlikely that you will get sued for clearing snow/ice, in fact they encourage it.
Hi The problem is that by salt/gritting you are changing the condition of the floor and it would be your fault if anyone slips on that floor.I am not saying to work and not spread salt/grit just that you change the condition of the floor its your fault.by useing wfp your changing the condition aswell.
ive never put salt or grit down . and ive only had 3 custys slip and break bones . one was a pensioner who broke her hip and collar bone . i dont think thats bad going in nearly 30 years