TTM requires some work and particularly diligent execution but it is the best to make sure new fish don't bring Ich into your tank.
Unfortunately, by itself, it only works against Ich (Cryptocaryon).
Though since the fish go to new sterilized tanks every 3 days you can do formalin/malachite green baths during the transfers to eliminate possible Amyloodinium, Brooklynella, Trichodina or Uronema infections (and transfers of free ich stages with the fish).
And while in the tanks you can dose PraziPro to clean up flukes and intestinal worms.
So in combination with the above mentioned additions TTM is the ideal preventive quarantine measure for new fish.