I found my log on the Greenex treatment. This is what worked for me, it may not work for you. I hope it helps.
One quick update. They are starting to come back. I think there were some in my nano. sad. I will probobly treat them again soon.
RR
After reading about some success with the use of Greenex as a treatment for flatworms I decided to try it. I have a 50 gallon reef tank that has been set up for 2 years and have had a problem with flatworms for 8 months. I tried siphoning methods, but many of the flatworms are on LPS corals, and they get injured by the siphon. I also tried freshwater dips, but this is not possible with some of the corals in my tank. I kept a log of what I have done in case it is useful to other reefers. I am not a scientist, but I tried to be as thorough as possible. If you have any questions or comments please contact me. Although it seems like this treatment has done the trick for me, attempt it at your own risk.
3:30
Turned off all circulation pumps and main pump. Skimmer was left running but is in sump and only skims when main pump is on.
Mixed 5 drops of Greenex in a cup of tank water. Added to the tank via turkey baster. Targeted at coral with lots of flatworms. The flatworms seemed unhappy and sorta shriveled up.
Fish or corals show no reaction to the Greenex.
3:45
The flatworms seemed the same, but a lot of them were moving. Repeated above with the same results.
Fish or corals still show no reaction to the Greenex.
4:15
Repeated actions of 3:45. Noticed much more motion of flatworms than normal.
Fish or corals still show no reaction to the Greenex.
5:00
Circulation pumps came one.
Noticed two or three flatworms floating listless in the water. When the hit something else in the tank they seemed not to move.
Other flatworms seemed slightly disoriented - lifting the front part of their body, but not seeming to know how to put it down properly.
Fish or corals still show no reaction to the Greenex.
5:15
More floating flatworms, maybe 8, some seem to move a little when they hit the substrate.
Fish or corals still show no reaction to the Greenex.
5:30
Main pump started again. Many flatworms blowing about in the current. Some seem dead, others seem to be trying to swim, but not coordinated. Others seem to be folded in half and twitching in what I hope are death throws.
Fish or corals still show no reaction to the Greenex.
6:00
Caught two flatworms free swimming. Put them in a cup with tankwater and 2 drops of Greenex. The started to swim like crazy then folded in half and did the death throws. They died and soon I could not tell where they were in the cup anymore.
Fish or corals still show no reaction to the Greenex.
6:30
I see much fewer flatworms than before treatment. There are still some here and there, and some that seem kinda healthy on some mushrooms that are far from the target area of the previous treatments. I am thinking of mixing up 5 more drops of Greenex, for a total of 20 drops - them maximum amount I pledged to use in this trial.
6:45
Added the 5 more drops, mixed in tank water, discussed in the 6:30 entry. Turned off main pump again.
Preped Magnum 330 with fresh carbon, 1/2 a polyfilter and foam sleeve filter for later to filter out Greenex and bodies of flatworms and flatworm toxin. Also started airating and heating 5 gallons of NSW for water change.
8:30
Started running the Magnum, but have not done the water change. There are still some flatworms, but only about 10% of what was there when I started the treatment.
I will add to this log in the next few days to bring it up to date.
Quickie conclusion:
This treatment has seemed to work pretty darn well for me.
It is possible that the flatworms are hiding and just injured - though I do not think this is the case. It is also possible that the treatment will continue to kill the remaining flatworms. The corals, fish and other critters in the tank have shown no bad reactions, and it is possible that the will in the future - though I don't think this the case.
Addendum:
8:00 am the next day.
Did 15% water change. The magnum with the carbon ran all night. Everything looks good. Could only find one flatworm. Abalone was munching, and the snails were out in force.
It worked ok at first didn't see any flat worms after using it ( and boy I had a lot ). But I must not have got them all. They'er back with avengeance. I may have made super worms. 
