kindness, moisten
渥 centers on a gentle, nourishing wetness that conveys kindness and care. The idea of moistening something is linked to a generous, benevolent act, like watering a plant or soothing with moisture.
渥 combines the water radical 氵 with 屋, which likely contributes the sound アク. The water radical suggests moisture, and the character came to express the idea of moistening and, by extension, kindness.
Water 氵 flows into a house 屋, moistening everything inside with gentle kindness. Picture a caring person watering the plants inside a home, spreading both moisture and goodwill.
For アク, imagine a kind act of moistening a dry garden: act -> アク, and the water from the left side performs this generous act.