I find that ACV anywhere near my scalp makes it incredibly oily. I would carry on with the Rhassoul clay, but mix it with only boiled water that has cooled down. I make my mixture fairly runny, drizzle it on dry hair, massage it in, comb it through, wait 5 minutes while I do other things in the shower, then rinse well. You can follow up with a water-ACV mix, rinsed off after about 30 seconds on the ends if you like, but I don't find this necessary. If you are concerned about dry ends with the clay wash, you can also apply a small amount of a mixture of honey and oil (such as coconut or jojoba) on the ends the night before you wash, and sleep with it in; the clay will wash it right out in the morning and the honey-oil mixture will protect your ends. Hope this helps!