Add a tiny little bit of food coloring to the bowl with the shampoo and mix it together well.
Add 2.5 cups of cornstarch to the shampoo and food coloring mixture.Stir it together well using your spoon. It should form a crumbly texture.
Start to add water to the bowl gradually.I recommend adding 1-2 tablespoons of water to begin. Mix it together well.Then, add another 1-2 tablespoons of water and, again, mix it together well.Keep adding 1-2 tablespoons of water at a time. You can stop when the mixture has a soft consistency.
Now, take your slime out of the bowl. Knead it like you would dough.The slime should be soft and stretchy.
Your DIY shampoo slime is complete.The slime will eventually get dry, so it should be stored in an air-tight container to prolong its life.If it dries out, you can add some more water and re-work the slime.Enjoy!
Notes
* You can use either powder or liquid food coloring for this project. It really doesn’t matter which one you use, so if you have some food coloring at home already, just use that!