I recently redid a bathroom - all but the tile floor. In the process of installing a new tub, I had to replace five tiles. The issue is the grout is close to the old grout (little over 10 years old) but not a perfect match.
Can you actually regrout over existing grout without "rotozipping" out the existing grout?
I have been told you can etch the existing grout and then skim with the new grout.

