The abrasiveness is what makes it an effective cleaner. Diamond is exceptionally hard; much harder than melamine.
Yep, my buddy who is an engineer and builder at Soundsmith uses a specialized xacto knife to scrape hardened ‘gunk’ off a used diamond stylus (under high magnification) to bring back to life when possible. Doubt Magic Eraser is going to do any harm because of its abrasiveness.
He is also a huge proponent of BluTak and Magic Eraser before/after each spin.