The scalp can get build-up just like the length, I get that all the time. How you can tell if you have scalp build-up: you see flakes when you don't usually have flakes, you see extra stuff on the root of your shed hairs, you notice your scalp isn't feeling like it's usual self although nothing changed in your routine (or the weather). The following two methods are the best way to get rid of it:
- Scritching: hold a narrow tooth comb parallel to the scalp and gently move it back and forth to remove build-up. This method is free, works best on detangled hair while using either a bone comb or a wooden comb. For me personally this method is very difficult because I have a tough time being gentle and end up harming my scalp (every freaking time, sigh).
- Scalp scrubs: mix extra virgin olive oil with granulated salt (this is my absolute favorite). I have seen a lot of recipes using different oils, usually mixed with granulated sugar (especially brown sugar), but my scalp is itchy and I know that certain fungi and bacteria feed on sugar (like the yeast malassezia associated with Seborrhoeic dermatitis), I'd rather NOT feed mine and I've had way better results with Epsom Salt
than with sugar. Epsom salt is used for treating skin conditions (saltworks), it is also a treatment listed for psoriasis (Flaky (and/or itchy) scalp causes and treatments). You can use any oil you want as long as it is in liquid form while you use it on your scalp (lighter oils are better than thicker ones, and in the flaky scalp entry I linked above you can find some anti-fungal oils and essential oils to use if you have dandruff). Some people like to use conditioner, but since it usually has water as one of its ingredients, it ends up melting the sugar/salt thus defeating the purpose of exfoliating so I would NOT recommend it.
Application: I use it before wetting my hair, in the shower by massaging my scalp with the scrub, then I wash my hair after I rinse out whatever I can with water. I do this instead of wetting my hair first then using it as I would a facial scrub or a body scrub because wet hair is very fragile and the oil helps distribute the scrub all over my scalp just fine.