Cleaning gutter guard before use??

I would return it and tell them that you have seen this item at out places and it does not smell and you want to exchange it for a new one that does not smell.
Things get spilled on all the time in shipping crates get broken and so on. I have seen this before when I worked at Canadian Messanger we would be unloading trailers or trian cars and stuff is broken all the time before we got to it.

Bill