Simple Water Play
I love a tuff tray (the children use them in Early Years and KS1 at school for play activities and you can pick them up on Amazon for less than £20) but today ours was still dirty from an activity I had done a few days ago.
Not to worry. I put it out against the fence with some warm soapy water and sponges and let the children wash it.
They also washed their mud kitchen pots and pans, their Little Tikes car, and each other! A full hour of absolute absorption in what they were doing. For older children, they could start with washing their bikes or scooters, small world characters (just the waterproof ones obviously) or anything else. Just follow their lead and be prepared for one of them to sit in a bucket fully clothed!