I see what your plan of attack is and all I can say is that you are missing the most important part of getting rid of your problem, The eggs.
I don't know how effective your plan is however, I got this procedure from several people and it worked great.
Since you can remove the colonies it should be easier for you to erradicate the nudi's quick. Place them in a quarantine tank. set up an iodine dip in a separate bucket. If you look at the lugols solution bottle you will see a solution for using as a dip. make the dip solution in a small bucket large enough to soak your largest zoa colony. Soak each colony and give it a few shakes while in the dip solution. At this point you will start to see the nudi's in the bottom of the bucket. the solution will kill the nudi's but it will not kill the eggs. Take a magnifying glass and a pair of tweezers and look for white spiral strings, these are the eggs. take these off with the tweezers. once done, dip and shake again. If after several colonies, you have a lot of nudi's then dump it and make another batch. once you are done with all the colonies, place them in the quarantine tank and keep an eye on them for possible left over nudi's. you can also place a coris wrasse in this tank since it will not be medicated. the wrasse will eat any stragglers. Keep this quarantine until you can no longer see or find any eggs or nudi's. then you can place your colonies back into your DT. do the dip every week if necessary. The Iodine is a disinfectant and will help your zoa's recover. By the way use gloves when doing this and goggles. because the nudi's eat the zoa's they will contain the exact same toxic chemical in them, just be careful and take some precautions.
Hope this helps. good luck
