Is a glass foot file better than a metal rasp?

Glass (often marketed as nano-glass) files are popular for finer smoothing and easy rinsing, and the Dr. Scholl's nano-glass file holds a strong star average across nearly 19,000 ratings. Metal rasps like the Colossal-style files remove hard skin faster and have far higher review volume, but reviewers note they can be more aggressive. Glass tends to suit thinner calluses and finishing; metal suits heavier buildup.