Green’s Dictionary of Slang

(UK black) to persuade, to sweet-talk.

[1796		T. Morton Way to Get Married Inchbold (1808) XXV 12: As they had plucked me of the last feather, I got up, and, in imitation of my betters, twang’d off a few dam’mes, and retired.].
1966		(con. 1940s) L. Bennett ‘Recruit’ Jamaica Labrish 92: Him noh even get him ticket / But yuh want fe hear him twang!
2003		Dizzee Rascal in Vice Mag. at Hyperdub.com 🌐 I can talk my way out of things. I twanged – twanged means to try and persuade someone – my way out, make them think maybe they shouldn’t [have a kid], regardless of if they really want it. I, like, twisted their minds around.
2018-20		T. Thorne (ed.) ‘Drill Slang Glossary’ at Forensic Linguistic Databank 🌐 Twang - smooth-talk, persuade by flattery.