NAC 467.598 Physical appearance of unarmed combatants. (NRS 467.030)
2. The excessive use of grease or any other foreign substance may not be used on the face or body of an unarmed combatant. The referees or the Commission’s representative in charge shall cause any excessive grease or foreign substance to be removed.
"I believe he will run away the entire fight and I'm prepared for this... If he runs, I’ll run after him"
-Thiago Silva on Lyoto Machida UFC 94 Fight