I would use muriatic (hydrochloric) acid. I’ve never been impressed by vinegar as a rust and/or calcium deposit removal solvent, although you will then need to throughly strip it after rust is removed and coat it with a layer of some heavy oil because it will remove any passivation layer and leave the metal open to quickly rusting again.
This guy likes something called “Krud Kutter”; never used it, don’t know what the active agent is, but it does appear to work:
Stranger