I did that about a decade ago. My hair was greasy (to me) for a short time until my scalp figured out how to maintain its own balance. Literally no one could tell I wasn't using shampoo and my hair was silky. I finally told my husband after about 4 months and he said "ew". So I went back to shampoo but it's so true that it strips your hair and then conditioner supposedly puts the nutrients back. Same for facial cleansers and whatnot. I forgot about that hair experiment I did! Inspired to revisit that and next time keep my mouth shut 😂