I second that on the pencil eraser. You would be surprised what a pencil eraser will do for a knife blade. They’re also good for cleaning your ceramic sharpeners.
Update: tried the eraser and dang, it did a number, not perfect but big improvement. Then I got the dumb idea to take a white crayon and fill it in that looked awful so I tried clean it out but only got some of it. Guess I need figure out what maker of etchant I need and order some as I have lots of knives I could etch. Ordered my first set of handles from the knife connection and am beyond pleased! Can’t believe how grippy they feel. I hope to add more. Now I need to find a sheath for it and I’ll be ready for anything any suggestions?
I have used a toothbrush and toothpaste- crest if I recall- worked great. Also used baking soda and a bit of water to make a paste and a soft bristle brush- worked better than toothpaste.