This comment came in from John. Just after the halfway point of Whacking Day it highlights an important point:

Thanks to a lot of hard work, an excellent snake-to-egg ratio, and my egg buddies, I expect to have all of the prizes well before Whacking Day.  Once I have the Sleep-Eazy Motel, I would rather that the folks that have been leaving me eggs leave eggs for other players who still need them.  Do we have a way to let people know not to leave any more eggs?  Should we leave an egg or something in front of the motel to let others know not to leave any more eggs?  Or has everyone stopped leaving eggs for anyone that has Miss Springfield?

If your friend has all of the prizes at this point, there’s probably no need to give them eggs. It’s far better for you to give them to the people in your friend list who are behind the day’s target and need a boost to help them get the prizes by the time the event ends.

You can keep track of which of your friends have 12,500 eggs or more through Lisa’s task to release snakes from another town. More importantly, you can also keep track of which of your friends have only a few thousand eggs and need an encouragement boost. While the people at the top end now have the Whack Boxes to work towards, they’re really nothing special, and I’m sure most would be far happier to see all those eggs go to people who really need them.

And if you really want to indicate that you don’t want or need any more eggs, why not follow John’s suggestion and signal this by leaving just one egg in front of the motel.