Yes, that works and I occasionally used it for small corrections. No, it's not written down and not in the Part B2a. Switching off Centre pumps with fuel remaining in the centre runs the risk of centre tank fuel with less than full mains which has a limit of its own. Balancing by asymmetric use of centre pumps runs the risk of imbalancing the other way - if you're balancing using the mains/crossfeed you've got the option of leaving the pump EICAS messages visible as an ongoing reminder. Not sure how you could have a big main tank imbalance with normal Boeing fuel use - empty the centre then use the mains - long use of APU perhaps or poor refuelling operator. You could argue that good SA, knowledge of ac systems etc would allow you to do what you want on this!
So what do (did) I do? Ignore imbalance until centre empty then sort it or occasionally do some recreational fuel balancing.
hth