After completing the above steps across the whole floor, wait 20 to 30 minutes to allow the grout time to harden a little. Using a bucket of clean water and a large flat sponge, dampen the sponge and wipe it across the tiles in a diagonal direction. Roll it slightly upwards as you wipe to remove excess grout but try not to disturb the grout between the tiles. Rinse the sponge after every wipe and squeeze it so it is just damp. Keep the sponge as free of grout as you can during this process.