The uncertainty principle here is which parents will punch you in the face.
Listen up, guy making blue-meth rock candy on Etsy: there's kid Halloween and there's adult Halloween, and never the twain shall meet. Candy is for kids. Inappropriate references to drugs are for adults (but for women, it has to be a sexy inappropriate reference to drugs). Inappropriate candy references to drugs are just asking for trouble. If you buy this, you will have parents angry at you that their kids are learning about drugs from you when they should be learning about them from their low-achieving friends. Worse, you will probably end up with meth addicts who are angry because they only want sugar after they have their meth. So be wise and get someone else to distribute.