I've spent a lot of $ on a lot of devices to sharpen hooks and knives, and for the last season I've wished I never had. Absolutely the best hook and fillet knife touch-up stone I've ever used is the DMT angler's -or- diafold pocket stone. I highly
recommend picking one up. After a season of use ZERO rust and it was still putting a sticky point on even the hardest S/S hooks.