Train it on this - a great resource: http://www.gdeltproject.org/

I remain skeptical that merely flagging individual content as 'probable disminformation' will the address issue.

Propaganda is, at its core, a form of psychological manipulation. It doesn't necessarily have to involve overt lies. Omission of facts, tone, phrasing and choice of words, etc. are all effective tools.

There are patterns to propaganda. /That/ is their achilles heel.