In Counter-Strike Online (CSOL), the Holy Water Grenade is a grenade filled with holy water, featuring strong continuous damage. It can be used in Biohazard Mode Ⅱ and Biohazard Mode Ⅲ after selecting Fernando. With a Bio-Weapon License, it can also be used in Catastrophe Mode.
It deals approximately 110 points of continuous damage per second to zombies within the explosion range, lasting about 8 seconds, with a total damage of over 1,500. However, it cannot directly kill zombies. If it explodes directly on a zombie, the zombie's health will immediately decrease by 1,000.
When facing the invisible "Shadow Barbie", the explosion splash can make it briefly visible, with blue flames appearing on its body for a few seconds.