If you are the SLIGHTEST bit suspect, as in they didnt look healthy at the LFS, you know it is a fresh wild colony, or you got them online, I would give them a 2 minute half a capsule of furan II / 1 cup of tank water dip. Wont hurt them at all and you will sleep better at night.
I also use the Furan II, but add a few drops of FlatwormExit and let them sit for 10-15 minutes and haven't lost any yet. I do this with all the new corals I put in my tank. It will not kill any eggs on the corals, but it should get rid of any other pests.
I made the mistake of putting zoas that I had gotten from a friend in one of my old tanks and with them came Nudis and it wipped out my entire colony of Bam Bam Oranges before I could get rid of all the little pests.
I also use the tropical marine pro coral cure on alot of my corals. After I run them in the Furan and FE dip I will put them in a bath of TMPCC for a few minutes, but I too have never used it on the zoas so I would be interested if anyone has. I know Kent's version says on the bottle not to use it on polyps.