A Stunt, Not a Protest
They were not "plants" of the campaign. But neither were they real anti-female protesters. The whole thing was an adolescent goof that allowed Hillary to look good and remind her base that sexism was alive and well.
As radio stunts go, it wasn't nearly as good as Stuttering John asking former Bill Clinton mistress Gennnifer Flowers whether she planned on sleeping with any of the other candidates.
Both worked to the advantage of the Clintons but the first was actually funny, the second, not so much.