Mayonnaise makes a great conditioner for dry hair. The vinegar helps with natural pH. You can make your own or use store bought.
1 cup of mayonnaise
plastic conditioning cap
Wet hair with warm water
Scoop mayonnaise onto your hair; gently massage it into your scalp in circular motions.
Work it down to the ends.
Smooth it all to the top of your head and cover with a plastic bag.
Leave on for at least 30 minutes.
Shampoo with a gentle shampoo as normal.