I did use one by Sonax (german car accessories company) that’s actually for cars and car parts, but it seemed to work. Actually it was mostly for the Stando Perun: it’s a “stainless” steel razor, but nevertheless catched a good amount of rust on its top and base plate. I suspect that the artisan simply forgot to apply enough coating, since all of the Stando razors are hand-finished. I just applied some to the Greencult 2.0 and RR Cyber Medium too since they were also cleaned thoroughly by me 🤷🏻‍♂️