How To Apply Castor Oil To Your Scalp For Faster Hair Growth. Castor Oil has been one of my staple products when it comes to my hair regimen. Castor oil is great for thickening your hair, getting rid of dandruff, and making it grow faster. You can purchase Jamaican castor oil online at amazon, and from your local health food store.Watch the video below for more tips when using Castor Oil, and be sure to subscribe to my youtube channel for more hair tips and videos.