What would be the best way to clean, sanitize, degunk old razors? I've bought eBay/Antique store razors and while in good shape they had years of soap scum and other crud in the crevices. I would like to make sure that whatever razor I'm about to use no longer has any of the previous owners DNA associated with it! It would also be nice to clean one of my razors properly before selling it to someone else.