I’m quite fond of the njoy line of steel sex toys, but they are certainly not cheap; $120 for a butt plug.
https://shop.njoytoys.com/products/pure-plug-2
If you’re looking for a less expensive option, Williams Sonoma has you covered; $29.95, including an optional “BDSM mode”.
https://www.williams-sonoma.com/products/reversible-meat-tenderizer/
“Tenderizer” indeed.