I think you're right. The Canadian Forces have never used them. I think Canadians would be pretty horrified if we did use them. It's almost a guilt by association concept when you enter into a joint operation, you in effect have to go to the “lowest common denominator” and participate, because in this case, the United States has no hesitation to use them in certain situations.
On May 17th, 2012. See this statement in context.