No clean up song, especially not the one by the Purple Dinosaur Who Shall Not Be Named.
No fuss. No tears.
Just four words: "Can you help me?"
"Can you help me put the scarves in the bag?" "Can you help me pick up the blocks?"
I routinely do programs for 1 year olds where when it's time to put the scarves away, or the bells, or the shakers, I use those 4 little words, and the stuff goes back in the bag or the container in LESS THAN TWO OR THREE MINUTES.
No fuss. No tears. They LIKE helping!
I always have 2 or 3 kids who really get into it and gather up lots of scarves. But they all help, and I thank them by name: "Good job, Amelia!" "Thanks for helping, Max!" "Good job, Lily!"
And if I DO get a fusser, I tell mom or nanny that it's fine for them to hold onto the item for a few more minutes. Usually they'll give it back as we move into another activity. At worst, I get it back at the end of the session.
Try this. It works.
And in doing so, you are not just teaching the kids something. Hopefully, the lesson crosses over to the adults......