R+Co Twister Curl Primer 147 ml / 5 oz

I have moderately curly, fine hair. Does anyone with similar hair use it as their only product and get good results?

Has anyone used this with a hair dryer diffuser?

Can black people use on their natural hair?

Do i need to also use curl cream? I currently use marc anthony curl cream but my hair stays tangled and feels greasy especially after sleeping on it