330I: Replacement Clones Melt After Children Get Sick From Excessive Freedom

As a child in the mid 80’s I read a book with a blue cover that only had the title (I am pretty sure it was the book cover as well), because I was trying not to judge a book by its cover. The book was science fiction about some children who were being replaced by clones of themselves so they could ditch school, and eat candy, and play- a little similar to a Pinocchio Treasure Island story. Until one day the children had stomach aches from eating too much, and not getting exercise, etc. and wanted to “go home”. I remember something about the rain melting the “aliens” or clones like cotton candy. I can’t remember much else and at first thought that maybe it was a Ray Bradbury book? At any rate I have been trying to find the title and would love if you could offer assistance.