If just doing it for general health I would probably go with ozonating cold water then drinking it immediately on an empty stomach. Use the white plastic aquarium diffusers, not the stone diffusers. How long you will ozonate the water will depend on the strength of the machine, the starter gas, the bubble size (the plastic diffusers increase the saturation rate), the temperature of the water and the volume of the water. On average though a glass of cold water should saturate with the ozone in about 10-15 minutes.
For head/eye problems you can do ear insufflation.