> fight trafficking
The message the cartel is sending to those who are trying to do exactly this seems like a strong deterrent.
Not saying it's a bad idea. But there is ample evidence of police not being paid enough and accepting "bribes" (I use quotes here because I think the negative connotation is unfair, somewhat, when a lot of this happens simply because they don't make enough in the first place - it's a different moral worldview when you're trying to support your family), so I don't know if it would be easy to stop them from being "corrupted", or "paid off", especially if the service is compulsory.
I think in general, the issue is super complicated, and if there were a simple panacea or idea, it would have been tried by now. I honestly don't know what can be done to stop the cartels with the amount of economic clout they have and how entrenched they are in all aspects of society.
There's a great line in Narcos (apologies for using a show, but I really think it's a very applicable line); a colonel was asked what he needed to stop Escobar, and he said "Incorruptible men".
Incorruptible men are very hard to come by. Incorruptible men who don't fear their families being slaughtered are probably even harder to come by.