Making my way through the joyless chore of cleaning the brake calipers and replacing the seals. It's a special kind of filth as you all know. A grime that laughs at soaps and solvents, with stubborn underlay of...something. Dried brake fluid? Inside the seal grooves to be specific. It's difficult to be effective at that weird angle and I'm not sure how tough the aluminum is. I want it squeaky clean, not scratchy clean. What say you, gentlemechanics? A smart and foolproof(ish) DIY solution is needed. I have the basics: toothbrush, q-tips, various cleaners (water and petroleum based). Any ideas from the brain trust? Thanks in advance.