Black Market Unlocks

[JannikDorum]

Hey guys,
I was hoping someone knew an easily accessible and, more importantly, free method to unlock items obtained through the black market.
Since I exclusively play zombies I only really care about one thing being the "cherry fizz" camo.

I thought it wouldn't be too hard to find a free way to obtain a single skin from the black market, but I was unable to find anything up until now,
Thanks in advance! )))