Lanolin is secreted by sheep to protect their wool keeping it in great condition. When my hair was in braidlocs I applied pure Lanolin to the ends after spritzing them with water. My hair stayed moisturised for days. Lanolin is too thick to be applied directly to all of my hair so I add it to my homemade hair balms and oil blends. As Lanolin is a surfactant with emulsifying properties it's easy to wash it from the hair with a sulfate-free shampoo.
If you decide to experiment with Lanolin be sure to purchase the BP, USP or EP grade to ensure that it is free from impurities.