chriscooper's owl is a completely different decor to the one Paul posted, it's one in which a rib mould has been used to incorporate the silver chloride salts internally.
The one Paul showed has a mosaic-like surface decor of silver chloride effects, and as John said, it is a hard decor to find, and only ever found on very small pieces. I'm not sure of the date, perhaps mid-late '80s/early '90s. I don't think it was continued for any great length of time, given the scarcity of this decor.
It is mostly found on owls. I have a little squat pot vase, about 2" tall and 3" wide.