I don’t know if “ionization” is the reason stainless steel removes smells. But it would not be a crock. Ionization would make a salt. Salts are generally not volatile. This would result in eliminating smells.
Especially with garlic, the Ni could easily form a sulfur salt.
Mike
That’s the sort of thing I was thinking; similar in principle to the trick for cleaning (actual) silverware with sodium carbonate or bicarbonate and an aluminum pan (If I remember the trick correctly).