Another idea, offer cash to all employees if they report with proof of the owner bringing in treif.
This should be made standard with all restaurants under hashgacha.
$5k if you show treif meats being used.
In JNB, one of the warning signs was an employee who told a mashgiach the owner was bringing in non kosher meats, but when the powers that be at the hashgacha tried to follow up, he had disappeared.