I've done a couple now, without removing the "guts". Not a problem, as long as you flush out any remaining water with something like Break-Free or WD40, after you finish. In retrospect, if I ever do a complete strip/ re-blue job again, though, I'll likely completely strip the gun to the bare frame, though. Then, it'll be a bit easier to get some edges properly blued and brightened - which is a problem with the hammer still in place, anyway.
All that aside, I have another tack on this. Why not simply NOT strip the gun.....and get some Brownell's OXPHO-BLUE....and use that ? I just recently used that stuff for the first time - and I cannot say enough about how WONDERFUL it is. NO water, NO stripping the old blue ! Only wiping down the parts with alcohol first. The Oxpho-Blue is tough, too. Unlike conventional bluing, you don't really have to be careful on the "brightening" step.....the Oxpho essentially cures instantly. It works much better on original bluing than a re-blued gun, however (I know this from personal experience). It even will blend and make disappear damage like holster wear, in which the bluing is worn off completely. If I were you, I'd just use the Oxpho-Blue and NEVER go back to conventional bluing - that's what I am going to do.
If the gun has deep scratches in the metal, not just bluing damage, then a conventional re-blue (with stripping and buffing out the scratches) might be in order. But, short of that kind of thing.....the Oxpho-Blue will do a tremendous job...and very easily.