flush down vs wash down

flush down and wash down both are verbs.

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

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

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