Thats looks like a texturzer. The curls dont look natural.
Anyway, coconut milk and lemon juice mixed with bentonite clay is a great natural "relaxer" for hair. It doesnt damage the hair, it just helps the coils have more hang. Them you would put gel or some kind of hair butter in your hair while its still wet. If you into natural stuff, you can make your own flax seed gel at home and mix in a lite conditioner for a semi natural hair gel with a hold thats not all crunchy and hard.