Grout removal

Submitted to Ask the Makers

I want to remove the grout from the floor of the shower. I started to do it manually using a diamond cutting saw but then thought I could use my Dremel oscillating tool for a Dremel. I bought the tile specific blade for the multi tool but I’m worries about technique...what is easier in terms of speed? I got nervous about damaging tiles because when trying to remove the grout the blade bounced. Anyone have suggestions? I searched YouTube but every video made it look so easy. These are 1 x 1 mosaic tiles. Good lesson in the dangers of Hans scrubbing tiles to reseal them. You see the cracks😀