There have been studies done with mixers that show even after using multiple of them, there are still tracks that can be followed. While they definitely help obfuscate things, they aren't the ultimate solution.
References please. Anyone using a mixing service can use the blockchain.info taint analysis tool to determine if there is any correlation between coins submitted to the service and coins received. A proper mixing service will return bitcoins with zero percent taint. No taint means that the coins you received back from the mixer cannot be correlated to the coins you sent. Everyone knows that mixing services are popular with darknet drug vendors so the coins you get back from the mixer might be traced back to one of the darknet markets. That would be a separate concern.
Will this work for you? There's been evaluations outside of MIT, as well, showing similar situations.