I looked into it briefly and Wikipedia suggests it did happen, but not the way it was presented.
It appears to me the theory became very widespread from when Maines made the theory, won the American Historical Association's Herbert Feis Award and was the inspiration for Sarah Ruhl's 2009 play In the Next Room and Tanya Wexler's 2011 film Hysteria. Until 2018 apparently when Maines conceded her theory was likely very exaggerated
"I never claimed to have evidence that this was really the case. What I said was that this was an interesting hypothesis" - Maines said, when her theory was challenged by Lieberman. But what did she mean?
From Lieberman's Wiki: Lieberman disputes the theory that Victorian doctors used vibrators to cure women’s hysteria. Lieberman traced the theory back to Rachel Maines’ The Technology of Orgasm, and while agreeing that sources do back up claims that Victorian doctors used vibrators to treat upwards of 300 different diseases (hysteria being one of them), none of the diseases were cured by vibrators.
On this same note, Lieberman also argues that Victorian vibrators were penetrative in purpose, and did not appear to be targeting clitoris stimulation
So basically vibrators were used but they didn't cure it? Maybe someone else knows more here