What is Lengua De Trapo?
an Argentine idiom refering to one who talks a lot of trash about others, of course this is meant negatively as its literal translation is "rag tongue." Technically it means one who gossips, but the phrase is structured similarly to one who is silver-tongued (a phrase, or idiom, for one who is gifted in giving speeches)
Nadie se salva de esta lengua de trapo
"no one can save him/herself from this gossipper"