Going to Mexico soon

Hi guys well my little brother has curly hair and we’re going to Mexico but not the tourist parts. We’re going to where our parents grew up and we’ve always had limited water there and my grandma is saying that there has been no water for like 2 weeks ( people are starting to go sell water ) and well here my brother takes like 40min showers and he will use up quite frankly all the water if she shows like that over there and I was just wondering if there’s any products that makes the hair look nice even days after not washing your hair thank you!