Expensive wusthoff knife set

Try using a steel cleaner!

have you sharpened them? If so, then oil them. And always dry them as soon as they are cleaned and don't set them in the sink after use in case water gets run into the sink. I had a set, loved them to pieces, but just recently got a new Calphalon set. Still have to baby them like the Wusthoff, but they hold their edge longer. I gave my Wusthoff to my daughter, and now she loves them to death :) Isn't it crazy how expensive kitchen knives are?

You might try Bartenders Friend. It comes in powder and liquid form. I use it for everything - glass stove top, sinks, pots, etc. works every time.

Clean with vinegar

touch of oil and wipe off

I solved this same problem with a paste made of dawn dishwashing soap and baking soda. Let it sit for a while then scrub off.