My mother's parents (& other family members) migrated from Arkansas to eastern Oklahoma over a hundred years ago. On occasion, I heard Granny & Grandad & my aunts or uncles refer to a few "witchin'" items, and one was a "witchin' peg." Evidently, there were a couple of old ladies they knew of who had such things in their houses very early on, around their little town of Dustin, Oklahoma. I was very curious, but never got to see them, as it was "of the devil."
I'll ask my mother to ask her oldest living sister if she rembered seeing one & could describe it. Of course, it was quite common for Grandad & most oldtimers to use a witchin' wand to find the right spot for a new well when the old one dried up, but that was the only "witchin'" item I can recall that they used. Since it was a Baptist preacher who worked that circuit in the early decades of the 1900's, one would NEVER use any such thing "of the devil" as a "witchin' peg!" That is also how the Irish & Scottish Music & dance--which led to the dance hall & drinking & the devil--was tossed aside back then.