Aha! Was looking for 'Fairy paint' for my little girl the other day, but they no longer sell it at the chemists. Didn't think of getting it from the feed store!
Isn't it just iodine too tho?
AFAIK the active ingredient in purple spray is chlorhexidine as opposed to Iodine.
I dare say either would be just as effective if used regularly, but the purple spray we buy comes in a pump dispenser so easy to get right into the frog.