I've seen some people asking about some Unlock All tools, so this is a free method to get everything unlocked on BO2 for the PC.
Step 1: Go to Barracks
Step 2: Go to Leaderboards -> Career
Step 3: Filter for All Players & All Time, and go to the top of the list
Step 4: Find a player named: "..4..<." (3136 games played)
Step 5: Go to Player Channel -> Edited Films
Step 6: Fully watch "Max Prestige Clip" first, then "Unlock all camos"
Still works as of writing this, no need for a trainer.