zirkonflex
You name it
For anything below C, just tune what would regularly be the "A" string using a tuner, and do the low/dropped string by ear. There is no way around it, fret at an octave and tune until it sounds right. This might also help if your intonation is slithtly off, but proper setup is the most important factor for recording reasonable guitar tracks, so go and intonate your axe.