we didn't, no, but we spent a lot of time sifting through our catalog, and there was a _tremendous_ amount of crap in there. We manually curated and purged shops that were obviously just dropshipping or looked like out-right scams.
I doubt it would be that easy, but, ya, using some form of automation is necessary. We devised a few rudimentary way to filter out the chaff, and it did quite well to remove the garbage. Still some would slip through, so it still required vigilance to remove them when you happen to see them.