The reason I'm asking is I noticed my flowerpot coral has some of the polyps looking brown and was wondering would a dip into a water and iodine solution could maybe help. I don't have any aquarium iodine but I have some household iodine.
Lugols solution is proven and most commonly used, but tincture of iodine and povidine iodine should be fine. I've never used them but have seen references where both have been used safely and effectively - but do so at your own risk... and dosages may be different.