personally, i don't believe in Zozo, outside of a hoax to scare people. but in any chase, cleanse and protect yourself, your home, and the board.
start with a cleansing bath, then cleanse your house. afterwards, make a protection amulet for yourself and your home, and shield yourself daily to keep negative energy away more so. finally, the board. cleanse it, protect it, and recharge it. as with the home and yourself, you can use the same items for the board. a simple way is to use salt water to wash the board, then pass it through sage smoke. this will cleanse the board of any energy. to protect it, you could say a chant, pass it through some incense with protective elements, or use a protection oil. after all this, charge the board with your energy, and leave it on your altar to be blessed [or however you would consecrate one of your tools.]
i recommend you cleanse your space before and after each session with the Ouija Board, and always cast a circle. you too should have a cleansing bath before and after use. this will cut down dramatically on the chances of a negative spirit being channeled through the board.
the key to the whole thing is to keep calm. if you panic, or doubt your cleansings/protection is effective, it will be weakened and might not effect the spirit in question. if this 'Zozo' is as bad as everyone claims, you might want to cleanse and protect a few times over the next couple months. if you feel the area is lighter, and you don't feel nervous/anxious then you've done it right and don't need to do it again. once you start feeling a heavy feeling and/or sensing something in your home, you should cleanse and protect again.