In theory I bet it's an efficient option. But I'm curious about the risks and costs involved in dealing with such "services", and how easy it is to find reputable thugs.
I used to know a guy who had an impressive physique and foreign accent and was hired for similar "communication jobs" (debt collection). It was all above board so he didn't carry any weapons and didn't do anything but the mere implication in his presence was often enough to motivate debtors to find ways to pay shortly after his visits. He was actually a nice guy and not much of a fighter.