water-washed vs washed

water-washed and washed both are adjectives.

Word	Noun	Adjective	Verb	Adverb
water-washed	No	Yes	No	No
washed	No	Yes	No	No

As adjectives, water-washed and washed are synonyms defined as:

water-washed (adjective)	washed (adjective)
clean by virtue of having been washed in water	clean by virtue of having been washed in water
washed or swept with water especially waves of the sea	wet as from washing; sometimes used in combination