You can use lots of different things to create messy play. Encourage your child to touch the materials and then describe what they can feel.
Is it hot or cold?
Is it wet or dry?
Is it hard or soft?
It is smooth or rough?
Can they describe something it feels like e.g. it feels like gloop.
You can use flour and water, cornflour and water, cornflour and hair conditioner, mud and water, jelly.
If you have time to do more than 1-how are they different?
Have fun and get your child to help to clear up the mess!