Gray residue on sheet pans/garlic press
I have a couple of jelly roll sheet pans and a Zyliss garlic press that are about 10-15 years-old and, after I wash them, I get a gray residue on the sponge when I wash them and on the towel when I'm drying them. I don't know what's causing this and I'm concerned that it may be harmful to continue to use them. I've never put them in the dishwasher and I only use Dawn dish detergent to wash them. Any CHer's know what might be causing this and whether, or not, I should continue using them?