blarney vs soft-soap

blarney is a noun but soft-soap is not a noun.

Word	Noun	Adjective	Verb	Adverb
blarney	Yes	No	Yes	No
soft-soap	No	No	Yes	No

As verbs, soft-soap is a hyponym of blarney; that is, soft-soap is a word with a more specific, narrower meaning than blarney:

Other hyponyms of blarney include browbeat, bully, swagger.

blarney (noun)	soft-soap (noun)
flattery designed to gain favor

blarney (verb)	soft-soap (verb)
influence or urge by gentle urging, caressing, or flattering	use flattering talk on somebody
	persuade someone through flattery