The main emphasis regarding efflorescence from both BAL and Mapei viewpoints seems to concentrate on the grout issues.
The effloresence problems that I deal with mainly apply to the natural stone I have been asked to Grind, Hone, Polish, Clean, Restore or Repair.
There are usually large areas involved. The most important factor regarding efflorescence is to find the cause because if you can't find that it will just keep reoccurring. Once I have found the cause provided the efflorescence is not too old (by this I mean hardened) the easiest and quickest removal method I find is to make a wire wool pad and use that. After all you need water to create efflorescence so if you dont use any it can't be created again. Failing this i.e. the salts have hardened or the wire wool has no effect I try various products i have at my disposal according to what material the efflorescence is on. I have in the past resorted to grinding it off. I then clean & treat accordingly with Eff Ex and Hey Presto
Kev