If water seeps into an older model of freezer or refrigerator, it will probably have to be discarded. Appliances with ruined insulation run continuously, frost up on the inside and develop bad odors.
Newer models with foam insulation may be all right. Have the refrigerator or freezer checked by a service person to be certain the equipment is in safe, working order.
Your part starts with disposing of any spoiled or questionable food. Also, remove shelves, crispers, and ice trays. Next, review the manufacturer's instructions on care and use of the refrigerator or freezer. Then wash the outside of the unit with a mild detergent, hot water, and a disinfectant. If stains are difficult to remove, try a mild cleanser or spray cleaner, being careful not to damage the surface.
It is okay to wash the inside of most cabinets with detergent and water. Rinse yours with a clean cloth and clear water; then wipe it dry. The plastic gasket which seals the door is likely to hold odors. Wash it thoroughly and rinse and dry it carefully. Rinse and disinfect with a disinfectant solution, such as two tablespoons chlorine bleach for each gallon of water.
After cleaning, leave the door open for about 15 minutes to allow free air circulation. If any odor remains, place several pieces of activated charcoal in an open metal container, or use a commercial refrigerator deodorizer. If odor still remains, wash with a solution of one teaspoon of baking soda for each quart of water.
Activated charcoal soaks up persistent odors. Spread about three ounces of fine powdered charcoal on a sheet of aluminum foil or in a shallow pan. Place this on a shelf in the refrigerator or freezer. Note: Foods can remain in the refrigerator with the charcoal. After six to eight hours, put the pan in a moderate oven (350 degrees) for 20 minutes. This reactivates the charcoal, so it can be re-used many times. Put the charcoal back in the unit and repeat the process until the odor disappears. Chlorophyll kitty litter also absorbs odors. If any traces of odor remain, securely wrapped frozen foods will not be affected! When you take food from the freezer, remove its wrapping and dispose of the wrapping immediately.
Resource:"Clean and Remove Refrigerator and Freezer Odors", University of Minnesota, Department of Design, Housing and Apparel, March 1997.