Synonyms for Wash out:

n.

kill off, squeeze out, interfere with, suppress, hold back, shut off, stamp out, cut into. scrub, swab, flush out, hose down, mop, Disinfect, swill. wash out (noun)
wash, wash away, rain out.

v.

cancel (verb)
scrub.
disintegrate (verb)
wash away.
eradicate (verb)
stamp out.

Other synonyms:

disintegrate
wash away.