I was looking for instructions as well, because I thought I had lost the manual. But then my wife found it. According to pages 8-9 (I scanned the pages as well and posted it here
Always be sure that the appliance is unplugged and switched OFF before cleaning or attempting to store the item. NEVER PLUG OR UNPLUG UNIT WITH WET HANDS.
DO NOT leave water in water tank or water basin when unit is not in use as it may result in the build up of mineral deposits and bacteria that can inhibit the output efficiency of the humidifier.
PLEASE NOTE that if the water remains in the water tank for more than a day or two, bacterial growth is possible.
ALWAYS use fresh cool water when using unit.
NOTE: When removing water tank, water may accumulate under vapor lid and on the bottom of the water tank. It is recommended to have a dry cloth ready to dry wet surfaces.
DISINFECTING THE WATER TANK AND WATER BASIN
1. Fill water tank with 1 teaspoon of household bleach in 1 gallon of water. Let stand twenty minutes, shaking vigorously with two hands every few minutes, drain and rinse with clean water until the bleach smell is gone. Dry with a clean cloth or paper towel.
2. Wipe the water basin with a soft cloth dampened in the bleach and water solution. Rinse the water basin with cool water to remove any bleach smell. DO NOT IMMERSE WATER BASIN IN WATER.
3. Wipe all exteriors surfaces of the base with a soft, dry cloth. Do not immerse the base in water or use water to clean the base. An electric shock may result or the humidifier may be damaged.
GENERAL MAINTENANCE AND CLEANING
Before any cleaning operation, switch the humidifier off and unplug it.
1. Always unplug the unit before cleaning.
2. The humidifier must be drained and cleaned before storing.
3. Once unplugged the exterior of the unit may be cleaned by wiping with a soft dry cloth. Caution: The ON/OFF switch must be throughly dry before unit is again plugged into power source.
4. There may be some lime deposits in the nebulizer, particular in areas with hard water. Overcome this drawback by cleaning the nebulizer with water and vinegar on a soft cloth regularly, as follows:
A. Dampen a cloth with vinegar and wipe the nebulizer gently, until the lime deposits disappear completely.
B. Rub down gently with a dry cloth and remove remains of humidity.
C. Do not rub the nebulizer with solid objects.
D. Do not clean with chemical products
5. When cleaning the water basin do not place the nebulizer directly under the water tap.
6. Never immerse the unit in water or let water enter the fan vent (see figure 3) or any other openings.
7. It is normal for water to be in the water basin. However water must not get inside the central body. If this should happen, take the humidifier to an authorized service center before using it again.
8. Clean the inside of the water tank at least once a week, as follows:
A. Fill the tank with clean water adding a few drops of bleach. Close the tank completely with its cap and shake by holding the tank with both hands. Do not hold by handle while shaking the tank.
B. Rinse thoroughly.