4 by 4 ceraminc tiles surround my bathroom tub
White non-sanded grout, 1/16th inch joints

I intend to regrout the whole thing rather than just the bad spot. Most
Most of the old grout is in good shape, albeit no longer bright white.

I've completely removed the old grout in a bad spot or two. As for the
rest... I was wondering if I can get away with lightly indenting the old
grout with a grout saw as opposed to trying to remove as much of it as
possible? This would make my life much easier.

Thanks in advance for any tips.