Mix the cornflour, salt and cream of tartar together. Set aside.
Heat the water and coconut oil in a pan. The coconut oil is white and waxy when cool, but changes to clear liquid when warm.
Remove from heat and stir in the shower gel and food colouring.
Add the dry ingredients to the liquid and then return to a low heat and stir until thicker. Add a little water or more cornflour if you don’t achieve the desired consistency.
Once cool enough to touch, knead to make a dough.
This will keep in an airtight container for quite a while.
At first the kids thought I was a little bit crazy when I gave them play dough in the bath, but they soon realised I was serious and absolutely loved it. It smells great, it’s squishy, and lots of fun. It doesn’t stain the bath (or the kids), it washes away easily and it cleans them as they play.