Porcelain dial cleaning
After seeing some photos on Ateliermadman's website and reading the original forum posts, I had to test this out myself—and the results are definitely worth trying. Using a dental cleanser tablet takes about 15 minutes for porcelain dials with glazed numbers. Fine hairlines disappear completely, and larger ones are significantly reduced. I've also successfully used this method on painted metal dials, though naturally, it can't be used on paper-based ones.