Right phonetic
喿 supplies the sound — zào shifted to zǎo through tone change only.
喿 itself depicts three
口 mouths above a
木 tree, picturing birds chirping in the branches. As phonetic in
澡 it gives the same vowel and consonant; same series produces
燥 (zào, dry),
噪 (zào, noisy),
躁 (zào, restless) — all sharing the zào rime.