Several years ago I bought a surface plate from Tru-Stone in St. Cloud, MN - Starrett bought them. I was inside the wearhouse and one of their employee's was filling a 1 gallon jug from a 55 gallon drum. I said "what you doing?" and he said he was pumping red Windex that they sell for $24.00" and laughed. I clean my plates with Windex I buy at the grocery store and white paper towels. Every now and then I slide a one sided razor blade on it too, no pressure, just to make sure it's clean. If the plate is stained with Dykem bearing blue I first buy Goop cream (no abrasive) hand cleaner and use that first, rub it in with a rubber gloved hand and keep cleaning / wiping it up with white towels until after I wipe the Goop and the white towel stays white..Then wipe the plate with your hand and fingers. You can feel the dirt with your bare hand.