Sweep the floor with a broom.
Wet the entire floor with a rag dipped in water. Clean one small part of the floor at a time with a combination of 5 parts water to 1 part vinegar. Scrub the floor with a stiff-bristled brush.
Wipe the floor with another wet rag and allow the floor to dry completely.
Use a small paintbrush or the applicator that came with your sealant to apply it to the grout. Be careful not to get any sealant on the surrounding tiles. Use a clean rag to wipe off any excess sealant. Apply enough sealant to completely saturate the grout to ensure you seal all of the pores.
Allow the sealant to dry overnight. Once the sealant is dry, you can return to normal activity on your newly sealed floor.