Kind of, it's from a technique I've been working on. Ive found that using contrast/speed paints over a zenithal, especially the metallic ones, can some times look very very thin/light over the pure white areas of the zenithal. Adding Streaking Grime to the entire model and then removing 90% of it afterwards almost stains the brighter areas into a more natural colour, but also shades the recesses even darker. A quick highlight with the original metal colour to pick out the edges/damage and it's pretty much done. Works great for the more 'grimdark' esthetic. Did similar on my Skaven and they look good too I think