I have been using TTM with a few modifications to keep my reef clean and has worked great for me. I dont find it stressful on fish much if done right and can take care of ICH, Velvet & most nematodes, parasitic copepods and flukes/external and internal parasites.
I use TTM with daily transfers to a clean bucket with new water from my reef each time. I also use Emamectin benzoate for 2 days in a row to take care of external and internal parasites that are not of protozoan origin(though there is some evidence on effectiveness on protozoans as well in the therapeutic dose) . The daily transfer guarantees to break the ice and velvet life cycle and also make for cleaner water and the opportunity to fatten up a weak fish. Also if there are any other serious bacterial infections, sores or protozoan infections, i treat for those as well(with antibiotics if bacterial or chloroquine if protozoan) till they are mostly gone
A good thing with daily water changes is also that you can easily do large fish without the need for too much water or large tanks. Large fish actually get to know you well and get to be pets even before they enter the tank, they dont mind the transfer at all. I always provide a tea or coffee mug for the fish to hide which i change in each transfer. Also for large fish or if the temp is low, i use a circulator pump for better aeration and the little extra heat to keep the bucket warm. I dont use a heater for ease of less things to clean. I keep the ambient temperature at 22-27C
This method and a good clean up crew have kept fish clean and healthy long term.