I'll be interested to hear the answers on this. If you have access to a blast cabinet, ground walnut shells do a wonderful job and will not disturb the chrome finish. 0000 steel wool 'can' work....but most people get impatient and start using more elbow grease than necessary, which will scratch the chrome. And if you're looking for mirror polish, don't go with steel wool.
A drill buffer wheel will work if you use the right polish...Mothers and Mequiars both make metal polish products. You can't remove the pits...only a re-chrome would help those. Hopefully. the guys here with mirror type finishes on their vacuums will respond.;-)
Kevin