I've been working at my present job for about 5 years now. ANd for the past 5 years, I've watched a homeowner meticulously 'pick' off white paint from stone (not brick). The results, as he goes, looks great! He has scaffolding, and he moves it around the house as he goes. I'm sure it's very comfortable to work in it instead of a ladder especially when you're up there for hours!
Like Henry says, it is a lot of work but it can be rewarding. I wouldn't be surprised if he's using dental tools. If you are really interested in knowing what you're up against, contact a brick layer, a restorer, or the local historical society. I'm sure somone can get you the info or at least point you in the right direction.