Before vari-audio (and Melodyne) I used to use the info line to retune vocals. Worked absolutely fine, but of course it was really slow to use! I’d put an autotune insert on the track as well but with slow response time. This then did a more precise job than I could be bothered to do using the info line, so it speeded up the process. As a final step, I’d export the track so I had it rendered with the autotune and if any bits exhibited odd autotune artefacts (like stepped glissandi when it should be smooth) then I just comped a bit of the raw tracks back in. In fact I still do this sort of comping thing today but using vari-audio instead of the info line!
Mike.