1. Use a paintball gun.
2. Fill water balloons with paint and throw them at the walls.
3. Paint with a sword.
4. Explode a watermelon with paint inside of it.
5. Put paint on the wheels of a rollercoaster and let it loose on the walls.
6. Use old rubber stamps.
7. Build a paint cannon.
8. Use candy, like a lollipop.
9. Use a drone to spray paint the walls.
10. Sprinklers should do the job.
11. Use a reverse vacuum cleaner.
12. Cut your hair and use it like a paintbrush.
13. A dog’s tail will paint the walls.
14. You can always use your tongue.
15. Use leaves.
16. Turn on a fan at high speed and throw paint in front of it.