Ultrasonic Piston Cleaning Test w/Simple Green Aircraft & Precision Part 1

I try out a 10%, 20% and 30% (remaining volume of tap water) ultrasonic cleaning solution on my pistons (cast aluminum), rods (forged steel), wrist pins (steel) and hardware (12.9 grade bolts). I find white discoloring of the piston crown and skirts plus a magnification of imperfections in the metal.