wash down vs flush down

wash down and flush down both are verbs.

Word	Noun	Adjective	Verb	Adverb
wash down	No	No	Yes	No
flush down	No	No	Yes	No

As verbs, wash down and flush down are synonyms defined as:

wash down (verb)	flush down (verb)
flow freely	flow freely
eat food accompanied by lots of liquid; also use metaphorically