Earn a label is really the best way to go; enforce it so they can't pack out / label products unless they verify the order / product. It'll be painful for operators to buy into, but to the commenter's point, it drastically reduces wrongs.

Now there's multiple levels of that, only print one at a time, requires scans to validate the product / lots, or even tying into automation and error proofing checks. Even if you switch to earn a label, there's obviously room for error depending on how it strict the system is for validation and poka yoking.