As long as the process used to artificially wear down a coin only involved wearing down the coin, then I don't know how that could be distinguishable from authentic wear. I mean if you try to AT the coin after, then I could see how they'd know.
But you wan the one that CAC declined to sticker, that would indicate that it was low end for the Poor-1 grade.
I think Bill Fivaz was one of the first to try to put together a lowball type set. He has a lot of certified P-01 and FR-02 type coins in a box labelled “World’s Worst Type Set”. This was years before lowball collecting became a thing
I knew collectors that were trying to put together "The Worlds Worst Type Set" years before the grading services even came into existance. So lowballers have been around at least 50 years. It just wasn't publicly well known until the Registry sets came about.