The less efficient you can make the process, the less you make it attractive to put resources into scaling it. Focus on making them generate the types of proof that aren't as easy to fabricate or at least give them as little information about why their initial approach failed as possible by playing along for a while after you catch on so they can't figure out how they got caught.
While what you are saying is theoretically effective, it assumes that enough people will do this to impact the business model… they won’t. So all you will accomplish is increasing human misery of trafficked slaves or their loved ones, while accomplishing nothing besides feeling a sense of retribution.
This problem requires state-level intervention, but it is mostly getting state level support.
The incentive alignment on this is not going to allow improvement. Perhaps if client nations imposed sanctions on nations that allowed this kind of industry, that could be changed.
You seem to be asserting that we should let them scam someone else. If you think that funding the scammers to protect their vicitm workers is moral then you should do it yourself rather than pawning the costs off on someone less aware who might unintentionally feed the scammers money they can't afford to lose.