I did mine on wet. I think it really depends on what you are doing it for, what results you want, your type of hair etc. If you are doing it for moisture (does it contain oils?), you may want to open up the hair first and steam/heat/water can help. If you are doing it more for scalp issues, then dry might be a better choice. It also depends on how sensitive your skin is, and how vigorously you plan to scrub ... I think you could potentially scrub your hair too rough and damage the hair with the edges of the sugar... but I'm really not sure of that. Just a tip from experience, if your scrub contains oils you'll definitely have to lo-poo after or you'll end up with a greasy head. I actually rinsed with just water after, and left the remaining oil for another day or so (wore a headband lol) because I had some major dry scalp issues going on. But again, it depends on what you are doing this for. Good luck, let us know how it goes I'm curious!