The essential idea is to remove material in a controlled, uniform way so that all pits are eliminated and the surface becomes flat and featureless. Routing achieves this by making planned passes with a cutting action that progressively removes a consistent layer of material across the entire surface. That controlled, systematic removal helps ensure pits aren’t left behind in spots you might miss with spot grinding or polishing. Grinding can remove material, but it’s more of a spot- or area-focused action and can leave irregularities if not used meticulously across the whole surface. Polishing finishes the surface after rough removal but relies on prior pit removal; it’s slower and isn’t typically the method used to guarantee complete elimination of pits. Etching chemically removes surface layers to reveal microstructure rather than to produce a uniformly pit-free surface. Therefore, routing is the best fit for removing material until no further pits are evident.