Answer first
Leftover shampoo can leave the scalp itchy or flaky. Rinse with lukewarm water for at least a minute after lathering, lift sections at the back and behind the ears, and run fingers along the scalp until hair feels clean and squeaky-free. Finish with a cooler rinse if you like.
Technique
Tilt the head back, work front to back, then lean forward for the nape.
Signs of residue
Itch after washing, dull roots, or flakes along the hairline.
Questions
Is hot water better?
Lukewarm is gentler on the scalp.
Does it matter for the tonic?
Yes, apply the tonic to a well-rinsed scalp.