A deep conditioning treatment for low porosity hair is done on clean hair, after shampoo. Apply your conditioner/mask on your hair by section to make sure that it's well spread everywhere. Once it's all done, it's time to wrap it and apply some heat! Wrap your hair in your tool of choice: the hood of a hooded dryer, shower cap, or warm towel. Apply direct or indirect heat for the entire duration of your deep conditioning. If you like to sauna, this is a good treatment to apply just before going in the sauna room, make sure if you do so, use a towel on your head to avoid overheating your hair. Let your hair sit with all that moisture and heat from 10 to 30min max. Then rinse with warm water (your low porosity hair don't need help to close the cuticle ;-). If you don't know yet how often your hair needs deep conditioning, start once a week and adapt based on your observations.