Here's what I'm talking about on the hand wheel, the inside is what I clean, with the sandpaper grit in the picture. Six hundred grit sandpaper is very, very fine. I clean the shaft with the same thing.
Also pictured is a paperclip thread guide on a Singer 127, I wrapped the paperclip piece around a larger screwdriver shaft to round it, and used a needle nose pliers to bend a small loop for the screw. Message me if you don't have the screw.