Fill your tub to the desired depth and get into the water. Place the bath bomb in the tub directly into the water away from where you are sitting in the tub. You can also choose to put the bath bomb into the water before getting into the water. As the bath bomb dissolves, it releases fragrances into the air and fizzes and bubbles. Relax in the tub. When you are finished with the tub, drain the water and rinse the sides to remove any bath bomb residue. Be sure to read any bath bomb packaging before using the bath bomb. Some bath bombs have specific instructions that need to be followed.