wash
澡 centers on cleansing with water: washing or bathing. The single given meaning is straightforward and concrete.
澡 combines 氵 (water) with 喿, which likely contributes the sound. The character is used for washing or bathing, fitting the water radical.
Water 氵 splashes beside the right side 喿, which looks like a cluster of mouths and trees. Imagine washing a noisy group of birds in a tree: the water cleans everything.
For ソウ, picture washing your soul clean: soul -> ソウ, and the water 氵 purifies your spirit.