The company will recycle old newspapers that are unsoiled, dry and clean.
From the ocregister.com
Obama couldn't, and can't, be seen as unsoiled and sui generis if his handlers talk too much about mechanics.
From the newsweek.com
This is true of Pryce's Timon in the television version mentioned above, whose plate is explicitly shown as being perpetually unsoiled by food, and he tends to be meek and modest.
From the en.wikipedia.org
More examples
Without soil or spot or stain
(unsoiling) The act or process of stripping the surface of dirt or soil from the top of a quarry, claybed, etc