Take the phrase "take a chill pill" a chill pill was originally a cyanide tablet the Germans (I think) would take if captures by the enemy.
Uh, the German forces in national socialist Germany by and large spoke German. That means that 'chill pill' would be loosely translated as something like 'kuhle pille', which loses pretty much all of its assonant and rhyming properties. What that tells me is that your etymology is wrong.
Anyway, the Confederate flag shouldn't be outright banned. We have a constitutional amendment that guarantees the right for people to hang up flags, even if said flags embody one of the worst periods in American history. As for infrastructure, it shouldn't be put on state-owned buildings.
However, if you think that the Confederate flag is a symbol of 'states rights' instead of slavery, you're an idiot.