Coconut oil has long been used in India and the South Seas for keeping hair soft and shiny. It has the added benefit of a lovely natural scent, that can remind you of Hawaii without the added expense of plane tickets. You can also use sesame or olive oil to massage the head and hair.
Massage for hair is generally a conditioning activity: you're applying oil to the hair and rubbing it in. it does make the hair softer, but even better, it tends to be relaxing to the scalp and neck. Having your head rubbed makes many people feel the way they did when they were babies. Once we're children, our parents forget to rub our heads, but when we're infants, they smooth our hair, pat us, and nestle us against them. Rubbing someone's head can be soothing, calming and loving.
Rubbing someone's head with scented oil can be downright erogenous. Use the oil warmed, and add rosemary or other essential oils to the base vegetable oil.