SOS pads do not have the acid that you need to remove the oxidation from the stainless steel knife blades. Remember that to remove an oxide, you need to set up a reduction reaction. The acid will break the bond between the iron and oxygen amd make the stains disappear. One thing that might be making the staining worse is a chlorinated dishwasher detergent or a lot of chlorine in your water since chlorine in solution with water releases oxygen making more oxygen available for bonding with the iron in your knife blades. It's like if you have iron in your water or rust in your washer and when you use chlorine bleach you get little rust spots on the white clothes. Then you have to treat them with Qwink or a similar acid product to remove the rust stain.