How often do you wet your child’s hair in the bath?

Question for mums of children with curly hair, how often do you wet their hair in the bath? I don’t mean wash, I mean just wet with water. We use a detangling spray and a leave in conditioner in the morning but his hair dries out quite a bit as the day goes on. I’m worried that wetting his hair every night in the bath might be drying his hair out. We don’t wash his hair with a shampoo unless he gets food in it and occasionally we will put a conditioner in his hair without the shampoo.