I've been trying to figure out a way to clean a waterblock that does not lend itself to clean disassembly. I've gone through gallons of Sysprep, Reboot, vinegar, distilled, and even a bit of Dawn, but there are still some hazes and spots on the inside that are stubborn. I know that toothpaste is a common cleaning agent for waterblocks, presumably for it's mild abrasive properties, and got to thinking; baking soda is a common household cleaner for the same reason. I was thinking of making a fairly stout water/baking soda mixture and trying to run it through that waterblock for a couple hours. I'm no chemist though, and I don't know how/if I need to be concerned about things like acrylic, nickle plating, or o-rings in the presence of baking soda. Any thoughts?