In this case, a lightweight, penetrating oil is going to be your best option. A lightweight, penetrating oil will help nourish your high porosity hair, whilst also avoid weighing your hair down. Some examples of a lightweight, penetrating oil include: RoseHip Seed Oil, Sweet Almond Oil, Avocado Oil or Argan Oil. You can find more examples in our Ultimate Guide to Hair Oils! If you find your hair feels oily after using one of these oils as your sealant, it may be a sign that you are using too much. Therefore, reduce the amount you are using and you should be able to use them without experiencing oily hair! The reason humectants as a sealant won't be an ideal choice for you, is because in dry/ low humidity climates, humectants can actually draw water out of your strands and into the air. This can then dry out your high porosity hair even more, which you certainly do not want as it can cause more frizz and damage!