Idiomatic meaning or allusion of "twirl a mustache" [duplicate]

Today, the New York Times online edition reviews a documentary film. The review contains the following sentence:

The filmmakers don’t villainize anyone, though a few participants come awfully close to twirling waxed mustaches, like an American manager who jokes to a Chinese colleague that it would be a good idea to duct-tape the mouths of talky American workers.

It's clearly nothing positive, but I have never heard of it, cannot deduce the exact meaning from context and could not find anything online, partly because most hits concern physical mustaches.

Solution 1:

In the sense of 'twirling waxed mustaches': Dastardly Whiplash

An oddly specific kind of character, the Dastardly Whiplash is a cartoonish villain taken from the silent film tradition [1891-1920]. Usually a Man of Wealth and Taste, in Great Britain (cough Evil Brit cough), he was generally a Bad Baronet; in the U.S., he was often an Evil Banker who held the mortgage on the heroine's farm. Physically, he's slightly hunched with an exaggerated nose and chin, a curling black moustache (all the better to twirl at you, my dear)

and: JSTOR

At home, too, beards and mustaches reflected a kind of masculinity that was falling out of favor. In 1920, Alma Whitaker, a Los Angeles Times columnist, complained that “tricky little mustaches” found on men returning from World War I

I appears from vaudeville to the the 'talkies' to the dashing soldiers of WWI returning, the twisting part came to connote 'evil design'. My sense would place this figurative usage in AmE at the turn of the 20th C.