Green’s Dictionary of Slang

carney n.1

[Yorks. dial. carney, cajolery, flattery. Despite the poss. link to carney n.2 , this use precedes it by a century; ult. ety. unknown]

soft, hypocritical talk.

[UK]W. Perry London Guide 205: The thoroughbred sycophant may be known by his carney, or small talk, or by his whining.
[UK]‘Jon Bee’ Dict. of the Turf, the Ring, the Chase, etc. 21: Carney — Love tales; also supplicatory intercessions, whereby the auditor is made to believe he has several virtuous attributes that he never before dreamt of possessing [...] ’Tis a word of Irish extraction, and first cousin to blarney.
[Ire] ‘The Musical Coalheaver’ Dublin Comic Songster 98: And I’ve been told by an old pal, / And I don’t think it’s carney, / That she can sing the ‘Oyster Gal,’ / As well as Caterlarney.
[Aus]Bell’s Life in Sydney 14 Mar. 1/6: There was one who would not stand his ‘Carney,’ Nor his ‘flummery,’ used at Killarney.
[UK]Hotten Dict. of Modern Sl. etc.
[UK]Hotten Sl. Dict.
[Scot] ‘Mister Barney’ in Laughing Songster 127: Och! Mister Barney, / None of your carney.
[UK]Newcastle Courant 2 Sept. 6/5: He has an oily jibb and is as good at carney as a cackle tub chicken.

In phrases

come the (old) carney (v.)

to flatter.

[UK]J. Manchon Le Slang 79: To come the carney, flatter, flagorner.