Castor oil for hair

I recently watched a video on YouTube about a 3 month castor oil challenge. The results that they had encouraged me to try it. First, hair is suppose to grow quickly and second, your hair grows thicker. I have extremely dry hair with a lot of split ends so, I was hoping the oils would also help fix my split ends. So far the overnight treatment works best. My hair is definitely softer but I go through a lot of castor oil.