I'm relatively new at working with laminated steel. I have a blade ground and hand sanded up to 1k grit. I have etched it with FC and it has great contrast right out of the tub. Now, once I spray it down with windex and dry it off, a lot of the black on the high carbon gets wiped away with the paper towel. Also, the mild steel gets all blotchy looking as well. Rubbing oil onto the blade helps with the contrast a little but the lighter steel (outer cladding) is still blotchy. If I use some Flitz to clean it up, the black on the core gets wiped away as well. What do you guys do in order to get a smoth clean look without ruining the contrast? My San Mai is Hitachi blue by the way.