I have never seen it in the midwest but heard it's popular in California. First time someone told me about it i didn't beleive them. They led me to beleive it is perfectly legal in the US although i dont know about different versions. It might be a similar case to "legal" absinthe.
I've never heard of it but I'm willing to bet if it is legal then it has been decocainized. Coca-Cola legally imports decocainized leaves from Bolivia for their soft-drink (the soft alternantive to hard liquor back in the day). The only legal permit that I know of for the real deal in the United States is for a company in new Jersey that makes medical grade cocaine.