Effect:
Magician has cup with pepper and water.

Volunteer puts fingers in water trying to separate the pepper.

This will not work.

Magician puts fingers in water and the water separates.

Supplies:
1- Water
2- Soap
3- Pepper
4- Cup
(make sure there is a sink nearby so volunteer can wash hand)

Secret:
Put water in a cup then regular pepper.
Before show, rub soap on your fingers (this will separate the pepper)