It's a real test of courage for some owners to bear the long wait without doing anything special to get him to eat.
During this phase, he isn't getting any fluids, so tubbing is the best way to get him to discover drinking. If he waits more than 14 days, he really does need the tubbing so his organs don't start to malfunction due to dehydration.
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Scroll way down to the Picky Eaters article. It's the state of the art info about this subject.