Summarize the following:
Mix a quarter cup of shampoo with equal parts water and add 2–4 tablespoons (29.6–59.1 ml) of oil. Sulfate free shampoos may prevent your scalp from becoming irritated and may stop your hair from becoming frizzy and easily breaking. With cornrows it’s important that you capture your hair’s natural oils to prevent frizziness.  Shake the bottle before applying the solution. You can use grapeseed, jojoba, coconut, or olive oil depending on what kind of hair you have. Coconut oil and jojoba oil work well for all hair types. Almond oil works well if you have dandruff. If you don’t have a spray bottle you can use a small bowl. Running your cornrows under warm water will open up your cuticles, and rinse the initial dirt out of your hair. Using a portable shower head can make this process easier. Shake your shampoo solution and apply it generously to your head and hair. If you're using a bowl, take some of the shampoo and lather the mixture in your hands. Once your hands are lathered apply it generously to your hair. Do not neglect your scalp. This area can have a lot of built up dirt and leftover residue from hair products you've used in the past. Use your fingers to gently massage each cornrow until all of them are lathered.  You should wash your cornrows every 7-10 days.  Washing your cornrows will prevent breakage when you take your braids out. Make sure that you rinse your hair thoroughly—for 3 to 5 minutes—to get all of the shampoo out of it. Leaving shampoo residue in your hair can irritate your scalp. Leaving shampoo in your hair could create residue build-up from the chemicals in your shampoo.

Summary:
Mix sulfate free shampoo, oil, and warm water in a spray bottle. Run your head under warm water. Spray your shampoo solution onto your cornrows and scalp. Massage the shampoo into your scalp and braids. Rinse your cornrows.