start with four drops. in a couple of hours, if that does the trick, then that much per day. if not, four more. up to twelve drops would not be excessive, but would be most effective. lots and lots of water.
remember this for food poisoning, too. any liquid the child can get down will do. if it comes back up wait 15 minutes and then give it again. its over in another 15 at most.
liquid suppository is a last resort but highly effective. take the chosen dose and dilute it enough to take the sting out of it but a small enough amount to be easily retained. my guess is one drop per ml of distilled water. no need to boil due to the iodine.
i say this because thats what i would do with my own. you can do what you want.