Davines › Oi All in One Milk Image 1 of 1 Oi All in One Milk $45.00 Lightweight OI All In One Milk is a multi-function leave-in spray treatment that softens, detangles, controls frizz and protects the hair from heat. Add To Cart Added! Lightweight OI All In One Milk is a multi-function leave-in spray treatment that softens, detangles, controls frizz and protects the hair from heat.