We've all been there, you are in the shop to buy a hair moisturizer (what youre really looking for is, an oil or grease like Dax..) and the only thing you are really looking for is a bottle with GROWTH written on it and then you go home use it as an addict. Your hair gets greasy or is drier than ever, your hair doesn't grow even though it says GROW FASTER so you tell everybody that it's wack and doesn't work. 

This exactly what me and a friend of mine went through but now that I think about it I realize that the product was just fine, we just didn't know how to use it.

If you are doing a pre-poo/oiling your hair or deep conditioner then you will probably be fine since you're gonna wash your hair afterwards. Oil is not a moisturizer so drenching your hair in oil will do more harm then good. 

When using oils you either give it time to get absorbed or seal your hair with it (check the LOC method).