We had to have at least one product that is messy. Stretchy sand is exactly what it's name says - kinetic sand that can be stretched - and stretched and stretched. It can get a bit messy and should rather not be played with on the living room couch, this one is for outside.
We bought this on a hunch and then struggled to keep them in stock, as every time the kids' friends hear that we have some more, we're asked to send some more to school.
They are available in 330 g tubs.