Its ok to have different methods. Thats the great thing about this hobby. Lots of different ways to do things. The reason i say to pull all the zoas out is the nudi eggs could and probably are in the zoas and if not removed will hatch. U can manually remove them with a razor but that is almost imposs. So you want to dip for 6-7 days in a row so when they hatch (which is fairly quickly) they will die. Zoas are very hardy and will be fine with the dip.
Edit: Call ur local petco or petsmart. I believe they might carry coral dip
Edit: Or u can order online from bulk reef or similar sight